diff --git a/modules/docs/src/Volo.Docs.Web/Pages/Documents/Project/Index.cshtml.cs b/modules/docs/src/Volo.Docs.Web/Pages/Documents/Project/Index.cshtml.cs
index 4f78353d07..ec8d7ad183 100644
--- a/modules/docs/src/Volo.Docs.Web/Pages/Documents/Project/Index.cshtml.cs
+++ b/modules/docs/src/Volo.Docs.Web/Pages/Documents/Project/Index.cshtml.cs
@@ -101,7 +101,7 @@ namespace Volo.Docs.Pages.Documents.Project
         public DocumentNavigationsDto DocumentNavigationsDto { get; private set; }
 
         private const int MaxDescriptionMetaTagLength = 200;
-        private const int MaxTocLevel = 2;
+        private const int MaxTocLevel = 3;
         private readonly IDocumentAppService _documentAppService;
         private readonly IDocumentToHtmlConverterFactory _documentToHtmlConverterFactory;
         private readonly IProjectAppService _projectAppService;