Abstract:InSAR technology is used to monitor the surface deformation in Shandong province. It is found that the surface subsidence is obvious in the Yellow River Delta and the southwest of Shandong province. The occurrence of these earth deformations have made the reliability of surveying and mapping datum results worse, which will seriously affect the application service of surveying and mapping datum. The elevation reference frame itself is dynamic, so it is necessary to carry out dynamic monitoring and maintenance of the elevation reference frame. Through fine processing of continuous observation results of CORS station network from 2015 to 2019, second order leveling observation will be carried out for CORS station, Class B and class C points, and benchmark in 2019. Through checking normal height value of CORS station through leveling results in 2015 and 2019, a new method of dynamic monitoring and maintenance of geodetic elevation reference frame based on CORS has been explored. It is also found that most benchmark have subsided, a few benchmark have been uplifted, and the data results of CORS and leveling also verify the monitoring results of InSAR on surface deformation.