In order to solve the problems of large number of pontoon bridge units, complex operation process, unclear operation situation and low efficiency of manual command in the process of pontoon bridge equipment erection, a real-time monitoring system for pontoon bridge motion state is developed based on Beidou RTK technology and wireless ad hoc network technology. Construct the system architecture, analyze the data flow, design and implement the hardware system and situation display software. A certain type of pontoon bridge equipment was tested in a certain section of the Yangtze River, and the results show that compared with the traditional erection mode, the time of pontoon bridge erection assisted by the system is shortened by 49.15%, and the centimeter-level high-precision positioning can be realized, which effectively improves the efficiency of pontoon bridge erection command and dispatch.