The development of GNSS observations have provided unprecedented large-scale and high-precision data which has acted as the model constraints for earthquake forecasting research. In this paper,we summarized the research progress of the application of GNSS in earthquake forecasting in the Chinese mainland,including the fault slipping feature description,dynamic deformation field analysis,strain concentration process identification,rupture risk judgment of the potential focal,and etc. Taking some typical earthquake events as examples,we analyzed the applications of GNSS data in the long-term,medium-term,short-term and imminent-stage earthquake forecasting. For the mid-long-term forecasting,a scientific idea of the time-space approximation for the strong earthquake are presented,that is,the process of plate boundary dynamic loading to large-medium scale dynamic deformation adjustment,to stress-strain concentration,to temporal and spatial approximation of the short and to medium-term rupture risk. On this basis,issues such as the improvement of GNSS monitoring capabilities,the identification of multi-scale crustal deformation dynamic information that related to the earthquake process,the construction of multi-parameter dynamic models with GNSS data are discussed and prospected. In general,the GNSS surveying has significantly enhanced the acquisition capability of the crustal deformation information for earthquake forecasting in the Chinese mainland,and enriched the scientific understanding of the physical process for the continental earthquake. Meanwhile,it has promoted the scientific ideas and methods developments for the continental earthquake forecasting,and accelerated the earthquake forecasting expansion from empirical to physical stage.