According to the specific needs of application software after the introduction of WLAN-bus-bridge in system, put forwards the related software design scheme of WLAN-bus-bridge. Combined with the time series model and event trigger model, the underlying ARM processor firmware was designed. In the background of WLAN interface, an instrument auto-discovery mechanism in line with the VXI-11 standard using socket technology was achieved. A series of system instrument management tools were established by developing VISA management library functions. The verification shows that the design can realize e real-time and reliable operation of a variety of airborne equipment bus interface, management interface and WLAN interface in GPIB instruments. The design can effectively simplify the system operation process, and realize the remote control in WLAN-bus-bridge hardware mechanism.