Abstract: Urban road subsidence is a key concern in recent years, involving urban road underground pipelines, water and soil quality and other factors, with hidden, sudden and destructive, so timely detection and investigation of hidden dangers is very necessary. There are a variety of physical detection means can be used for urban road subsidence detection. This paper takes some streets in Xining city as an example, conducts a large-scale survey of them through InSAR technology, and applies the integrated physical prospecting methods such as geo-radar method, high-density electrical method and surface wave method to the key areas where settlement anomalies appear, in order to compensate for the uncertainty and limitation of single physical prospecting, and finally implements the engineering means of drilling, it establishes a method from surface to line, from line to point, from shallow to deep, according to the advantages and disadvantages of different physical prospecting methods. The system has the advantages of high efficiency and low cost, and is suitable for the fine detection of urban roads in Qinghai's wet loess areas. The feasibility of the system has been confirmed, and it is recommended that a study of the development mechanism of the disease body should be carried out to provide a more scientific basis for the prevention of road subsidence.

Key words: InSAR, geological radar, high density electrical method, face wave method, road collapse