diff --git a/src/main/java/run/halo/app/model/dto/base/OutputConverter.java b/src/main/java/run/halo/app/model/dto/base/OutputConverter.java
index b803e1000..359f0fd78 100644
--- a/src/main/java/run/halo/app/model/dto/base/OutputConverter.java
+++ b/src/main/java/run/halo/app/model/dto/base/OutputConverter.java
@@ -1,5 +1,7 @@
 package run.halo.app.model.dto.base;
 
+import org.springframework.lang.NonNull;
+
 import static run.halo.app.utils.BeanUtils.updateProperties;
 
 /**
@@ -20,6 +22,7 @@ public interface OutputConverter<DTO extends OutputConverter<DTO, DOMAIN>, DOMAI
      * @return converted dto data
      */
     @SuppressWarnings("unchecked")
+    @NonNull
     default <T extends DTO> T convertFrom(DOMAIN domain) {
 
         updateProperties(domain, this);
diff --git a/src/main/java/run/halo/app/service/AttachmentService.java b/src/main/java/run/halo/app/service/AttachmentService.java
index 2013b7f9b..7fc836c29 100644
--- a/src/main/java/run/halo/app/service/AttachmentService.java
+++ b/src/main/java/run/halo/app/service/AttachmentService.java
@@ -1,13 +1,12 @@
 package run.halo.app.service;
 
-import run.halo.app.exception.FileOperationException;
-import run.halo.app.model.dto.AttachmentOutputDTO;
-import run.halo.app.model.entity.Attachment;
-import run.halo.app.service.base.CrudService;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
 import org.springframework.lang.NonNull;
 import org.springframework.web.multipart.MultipartFile;
+import run.halo.app.exception.FileOperationException;
+import run.halo.app.model.dto.AttachmentOutputDTO;
+import run.halo.app.model.entity.Attachment;
 import run.halo.app.service.base.CrudService;
 
 
@@ -45,4 +44,13 @@ public interface AttachmentService extends CrudService<Attachment, Integer> {
      */
     @NonNull
     Attachment removePermanently(@NonNull Integer id);
+
+    /**
+     * Converts to attachment output dto.
+     *
+     * @param attachment attachment must not be null
+     * @return an attachment output dto
+     */
+    @NonNull
+    AttachmentOutputDTO convertToDto(@NonNull Attachment attachment);
 }
diff --git a/src/main/java/run/halo/app/service/impl/AttachmentServiceImpl.java b/src/main/java/run/halo/app/service/impl/AttachmentServiceImpl.java
index 639ac91dd..57cfa40ff 100644
--- a/src/main/java/run/halo/app/service/impl/AttachmentServiceImpl.java
+++ b/src/main/java/run/halo/app/service/impl/AttachmentServiceImpl.java
@@ -1,5 +1,13 @@
 package run.halo.app.service.impl;
 
+import lombok.extern.slf4j.Slf4j;
+import org.apache.commons.lang3.StringUtils;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
+import org.springframework.lang.NonNull;
+import org.springframework.stereotype.Service;
+import org.springframework.util.Assert;
+import org.springframework.web.multipart.MultipartFile;
 import run.halo.app.handler.file.FileHandlers;
 import run.halo.app.model.dto.AttachmentOutputDTO;
 import run.halo.app.model.entity.Attachment;
@@ -10,15 +18,8 @@ import run.halo.app.repository.AttachmentRepository;
 import run.halo.app.service.AttachmentService;
 import run.halo.app.service.OptionService;
 import run.halo.app.service.base.AbstractCrudService;
-import lombok.extern.slf4j.Slf4j;
-import org.springframework.data.domain.Page;
-import org.springframework.data.domain.Pageable;
-import org.springframework.lang.NonNull;
-import org.springframework.stereotype.Service;
-import org.springframework.util.Assert;
-import org.springframework.web.multipart.MultipartFile;
-import run.halo.app.handler.file.FileHandlers;
-import run.halo.app.service.base.AbstractCrudService;
+
+import java.util.Objects;
 
 /**
  * AttachmentService implementation class
@@ -53,7 +54,7 @@ public class AttachmentServiceImpl extends AbstractCrudService<Attachment, Integ
         Page<Attachment> attachmentPage = listAll(pageable);
 
         // Convert and return
-        return attachmentPage.map(attachment -> new AttachmentOutputDTO().convertFrom(attachment));
+        return attachmentPage.map(this::convertToDto);
     }
 
     @Override
@@ -102,6 +103,29 @@ public class AttachmentServiceImpl extends AbstractCrudService<Attachment, Integ
         return deletedAttachment;
     }
 
+    @Override
+    public AttachmentOutputDTO convertToDto(Attachment attachment) {
+        Assert.notNull(attachment, "Attachment must not be null");
+
+        // Get blog base url
+        String blogBaseUrl = optionService.getBlogBaseUrl();
+
+        // Convert to output dto
+        AttachmentOutputDTO attachmentOutputDTO = new AttachmentOutputDTO().convertFrom(attachment);
+
+        if (Objects.equals(attachmentOutputDTO.getType(), AttachmentType.LOCAL)) {
+            // Append blog base url to path and thumbnail
+            String fullPath = StringUtils.join(blogBaseUrl, "/", attachmentOutputDTO.getPath());
+            String fullThumbPath = StringUtils.join(blogBaseUrl, "/", attachmentOutputDTO.getThumbPath());
+
+            // Set full path and full thumb path
+            attachmentOutputDTO.setPath(fullPath);
+            attachmentOutputDTO.setThumbPath(fullThumbPath);
+        }
+
+        return attachmentOutputDTO;
+    }
+
     /**
      * Get attachment type from options.
      *
diff --git a/src/main/java/run/halo/app/web/controller/admin/api/AttachmentController.java b/src/main/java/run/halo/app/web/controller/admin/api/AttachmentController.java
index 74e806082..0094d86f8 100644
--- a/src/main/java/run/halo/app/web/controller/admin/api/AttachmentController.java
+++ b/src/main/java/run/halo/app/web/controller/admin/api/AttachmentController.java
@@ -1,8 +1,5 @@
 package run.halo.app.web.controller.admin.api;
 
-import run.halo.app.model.dto.AttachmentOutputDTO;
-import run.halo.app.model.entity.Attachment;
-import run.halo.app.service.AttachmentService;
 import io.swagger.annotations.ApiOperation;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
@@ -10,6 +7,9 @@ import org.springframework.data.web.PageableDefault;
 import org.springframework.http.MediaType;
 import org.springframework.web.bind.annotation.*;
 import org.springframework.web.multipart.MultipartFile;
+import run.halo.app.model.dto.AttachmentOutputDTO;
+import run.halo.app.model.entity.Attachment;
+import run.halo.app.service.AttachmentService;
 
 import java.util.LinkedList;
 import java.util.List;
@@ -63,13 +63,13 @@ public class AttachmentController {
     @DeleteMapping("{id:\\d+}")
     @ApiOperation("Delete attachment by id")
     public AttachmentOutputDTO deletePermanently(@PathVariable("id") Integer id) {
-        return new AttachmentOutputDTO().convertFrom(attachmentService.removePermanently(id));
+        return attachmentService.convertToDto(attachmentService.removePermanently(id));
     }
 
     @PostMapping("upload")
     @ApiOperation("Uploads single file")
     public AttachmentOutputDTO uploadAttachment(@RequestPart("file") MultipartFile file) {
-        return new AttachmentOutputDTO().convertFrom(attachmentService.upload(file));
+        return attachmentService.convertToDto(attachmentService.upload(file));
     }
 
     @PostMapping(value = "uploads", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
@@ -81,7 +81,7 @@ public class AttachmentController {
             // Upload single file
             Attachment attachment = attachmentService.upload(file);
             // Convert and add
-            result.add(new AttachmentOutputDTO().convertFrom(attachment));
+            result.add(attachmentService.convertToDto(attachment));
         }
 
         return result;