Abstract: The operation interface of computer interlocking system needs to display the shape of the station and yard of the controlled object. For large-scale stations, the display effect of single display is poor, the graphics and text are compact, and it is not easy to operate and recognize. By modifying the multi-screen display hardware HDMI of AMOS-6000 industrial person computer to the video graphics Array (VGA) interface mode, the basic input and output system (BIOS) driver and basic graphics interface (BGI) file were used to implement the combination display of multiple displays for the DOS system. The scheme was applied in the engineering practice of Beijing-Shanghai existing general speed railway line, could meet the operation and display requirements of railway hub stations, marshalling stations and other large stations.