Because of the influence of working environment temperature, the zeropoint and sensitivity of piezoelectric pressure sensor often drift, so it needs to be compensated. A compensation algorithm based on least square method is discussed in this paper. The proposed algorithm is used to process the temperaturechanged data, so that the output of the sensor does not change with the temperature, and the problems of zeropoint drift and sensitivity drift of the sensor are solved well. The results show that the algorithm has a good compensation effect and is widely used in engineering practice.