Abstract: This paper mainly introduces the layout of mobile gravity monitoring network in China, and the gravity measurement data processing and extraction method of gravity precursor information. Mobile gravity monitoring results can reflects the image of dynamic evolution of regional gravity field and its tectonic activity characteristic. Based on a large number of observation data, the relationship between gravity variation and earthquake preparation is studied, and the ideas, ways and methods of earthquake prediction research are explored.The mid-term earthquake risk prediction research is carried out by using gravity observation data, and its results are used for earthquake consultation and annual earthquake trend prediction in time, which provide basises for the prediction of strong earthquakes and the delineation of annual dangerous areas in China. this paper points out the existing problems in mobile gravity monitoring in China, and puts forward the idea and thinking of using time-varying gravity monitoring data to promote seismic prediction research.