diff --git a/README.md b/README.md
index 89c6aa2..1dd15d3 100644
--- a/README.md
+++ b/README.md
@@ -107,7 +107,7 @@ The NanoKVM image is built on LicheeRV Nano SDK and MaixCDK, and is compatible w
 Note: Out of the 256MB memory in SG2002, 158MB is currently allocated for the multimedia subsystem, which NanoKVM will use for video image acquisition and processing.
 
 + [NanoKVM-A Schematic](https://cn.dl.sipeed.com/fileList/KVM/nanoKVM/HDK/02_Schematic/SCH_RV_Nano_KVM_A_30111.pdf)
-+ [NanoKVM-B Schematic](https://cn.dl.sipeed.com/fileList/KVM/nanoKVM/HDK/02_Schematic/SCH_HDMI_MIPI_31011.pdf)
++ [NanoKVM-B Schematic](https://cn.dl.sipeed.com/fileList/KVM/nanoKVM/HDK/02_Schematic/SCH_RV_Nano_KVM_B_30131.pdf)
 + [NanoKVM img](https://github.com/sipeed/NanoKVM/releases/tag/NanoKVM)
 
 ## Roadmap