Abstract: This paper proposed an improved coherent point target InSAR technology. The value of the sub-look coherent was used to identify the coherent point targets of small dataset, and the trend filter was then applied to remove the large-scale residual phase. Using 10 Radarsat-2 Wide Model images over Fuyang City during 2012—2013, the high density coherent point targets were obtained and the reliability of the results were improved. The obtained land subsidence was in accordance with the previous measurement data and our field survey. This method provides the technical supports and application example for risk analysis and the regular monitoring of the land subsidence in Fuyang City.