Abstract: By analyzing 6 month comparative geothermal observations in 3 wells at Shahe, Wenquan and Wusu stations, respectively, we conclude that the data obtained from the six observational instruments in these stations are reliable. The observations at the same depth of the Shahe and Wenquan well show that the overall trend and pattern, and even details, of the observed temperature variations are the same, and the correlation coefficient of these observations is close to 1. In the Wusu well the observation curves at the two depths of 250 m and 700 m are overall the same, but some details of the observations are deferent due to the sensors being at different depth.This article summarizes the specific operation method of installing two sets of digitalthermometers in the same well for comparative observation, and solves the difficulty in excluding the instrument trouble when abnormal observations appear.