Abstract The fixed point gravity non-tidal change data of the sinking balcony is stable, but the data have risen significantly for five consecutive months since June 2017, and the rate of increase is relatively large, with an amplitude of about 5 μGal/month, breaking the steady state of returning from the power failure in 2015. We investigate the instrument observation system and the regional geological characteristics: the GPS data began to decline in vertical component in May of the same year; computational analysis of GPS vertical changes cause the value of heavy forces (-1.714 μGal/mm) to be much smaller than the change in gravity; the station irrigated the flowers with water to do the gravity model simulation and calculated the disturbance change only 0.218 1 μGal, much less than the 5 μGal per month magnitude change disturbance. Through quantitative calculation and analysis of gravity changes caused by GPS vertical direction, calculation of water well pumping forward model, it is found that changes in external influences are not enough to cause the gravity and non-tidal anomalies; according to the comprehensive analysis 14.781 9 μGal, the gravity non-tidal change anomaly is an earthquake precursor anomaly. It thus provides a reliable basis for subsequent earthquake prediction.