Abstract: The application requirements of active radar for road condition detection of high-speed electric rail transit is discussed in this paper, and the research progress of relevant technologies at home and abroad is summarized. It is proposed to construct a multi-information fusion network radar system by using the power and communication network conditions along the line. The system comprehensively uses a variety of sensors to detect the track and surrounding conditions, upload the data to the cloud platform for data fusion analysis, and real-time data exchange with the running train terminal. The proposed scheme can not only provide reference for the dispatching system, but also realize the active observation of the running train to the road conditions ahead, so as to achieve the goal of safe operation of rail transit.