Abstract: Based on the static test of four CG-5 gravimeters for many years and the observation data of mobile gravity of Anhui survey network, this paper analyzes the long-term zero drift characteristics of CG-5 gravimeter and its relationship with temperature change. The following conclusions are drawn from the analysis of the drift characteristics of the instrument. The zero drift rate of CG-5 gravimeter changes greatly, and the amplitude decreases with the increase of time. The single period static test results show that the observed values of the instrument show a good linear rising trend after correction. The zero drift rate of the gravimeter has a good correlation with the ambient temperature. With the increase of temperature, the zero drift rate of the instrument will increase. The influence of temperature on the zero drift characteristics of gravimeter has certain hysteresis. The zero drift rate changes with the variation of the long-term background temperature of the instrument. However, the short term change of temperature has little effect on it.