Influencing factors and burial types play an important role in the precursor analysis of groundwater observation data.In this study,on the basis of the air pressure,rainfall,and water level data of two wells in the Ganyanchi pull-apart basin of Haiyuan,namely,the GYC and GYCN wells,the influencing factors of water level change were analyzed,and the burial types of groundwater were studied by using three methods: the step response function,frequency spectrum analysis,and phase advance/phase lag of the tidal wave group method.Results showed that (1) air pressure and rainfall are the primary factors affecting the dynamic variation in the water levels of the two wells.(2) As a result of circulation for a long period,disrepair,casing damage,and the great effects of surface water,the burial type of groundwater in the GYC well is mixed water,which is inconsistent with the type of confined water recorded in historical data.The groundwater of the GYCN well is confined water. The research results provide a scientific basis for the access (exit) mechanism of the water levels of observation wells and the position of future observation wells in the study area. Furthermore, the findings are of great significance for anomaly identification and earthquake situation tracking in the future.