diff --git a/application/src/main/java/run/halo/app/theme/finders/impl/ThumbnailFinderImpl.java b/application/src/main/java/run/halo/app/theme/finders/impl/ThumbnailFinderImpl.java
index 19a7922ce2..e8eac936b8 100644
--- a/application/src/main/java/run/halo/app/theme/finders/impl/ThumbnailFinderImpl.java
+++ b/application/src/main/java/run/halo/app/theme/finders/impl/ThumbnailFinderImpl.java
@@ -2,12 +2,14 @@
 
 import java.net.URI;
 import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
 import reactor.core.publisher.Mono;
 import run.halo.app.core.attachment.ThumbnailService;
 import run.halo.app.core.attachment.ThumbnailSize;
 import run.halo.app.theme.finders.Finder;
 import run.halo.app.theme.finders.ThumbnailFinder;
 
+@Slf4j
 @Finder("thumbnail")
 @RequiredArgsConstructor
 public class ThumbnailFinderImpl implements ThumbnailFinder {
@@ -15,8 +17,14 @@ public class ThumbnailFinderImpl implements ThumbnailFinder {
 
     @Override
     public Mono<String> gen(String uriStr, String size) {
-        return thumbnailService.generate(URI.create(uriStr), ThumbnailSize.fromName(size))
+        return Mono.fromSupplier(() -> URI.create(uriStr))
+            .flatMap(uri -> thumbnailService.generate(uri, ThumbnailSize.fromName(size)))
             .map(URI::toString)
+            .onErrorResume(Throwable.class, e -> {
+                log.debug("Failed to generate thumbnail for [{}], error: [{}]", uriStr,
+                    e.getMessage());
+                return Mono.just(uriStr);
+            })
             .defaultIfEmpty(uriStr);
     }
 }
diff --git a/application/src/test/java/run/halo/app/theme/finders/impl/ThumbnailFinderImplTest.java b/application/src/test/java/run/halo/app/theme/finders/impl/ThumbnailFinderImplTest.java
new file mode 100644
index 0000000000..3fb8d6e3b9
--- /dev/null
+++ b/application/src/test/java/run/halo/app/theme/finders/impl/ThumbnailFinderImplTest.java
@@ -0,0 +1,54 @@
+package run.halo.app.theme.finders.impl;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.net.URI;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import reactor.core.publisher.Mono;
+import reactor.test.StepVerifier;
+import run.halo.app.core.attachment.ThumbnailService;
+
+/**
+ * Tests for {@link ThumbnailFinderImpl}.
+ *
+ * @author guqing
+ * @since 2.20.0
+ */
+@ExtendWith(MockitoExtension.class)
+class ThumbnailFinderImplTest {
+
+    @Mock
+    ThumbnailService thumbnailService;
+
+    @InjectMocks
+    ThumbnailFinderImpl thumbnailFinder;
+
+    @Test
+    void shouldNotGenWhenUriIsInvalid() {
+        thumbnailFinder.gen("invalid uri", "l")
+            .as(StepVerifier::create)
+            .expectNext("invalid uri")
+            .verifyComplete();
+
+        verify(thumbnailService, times(0)).generate(any(), any());
+    }
+
+    @Test
+    void shouldGenWhenUriIsValid() {
+        when(thumbnailService.generate(any(), any()))
+            .thenReturn(Mono.just(URI.create("/test-thumb.jpg")));
+        thumbnailFinder.gen("/test.jpg", "l")
+            .as(StepVerifier::create)
+            .expectNext("/test-thumb.jpg")
+            .verifyComplete();
+
+        verify(thumbnailService).generate(any(), any());
+    }
+}