Abstract: For the mining process in the mining caused by rock and surface subsidence，threatening the surface of the mine residents and property safety issues.In this paper，an improved RTK-CORS measurement system is proposed by summarizing the advantages and disadvantages of the existing RTK-CORS technology，and the traditional Kalman method is designed.The improved whole system is applied to the field subsidence of a coal mine in Ordos In the experiment，through the error analysis and accuracy evaluation of the measured data，it is verified that the improved RTK-CORS system has high accuracy and high reliability and stability，and it is accurate and efficient for the future.Regional surface subsidence provides a reference for research.