The characteristics of two types of temperature and humidity sensor HMP45D and HMP155A at low and high temperature are analyzed. Using the automatic metrological verification system, three sensors of each type, and three temperatures, and six humidity points are selected to measure the accuracy and stability at different temperature points. The results show that the measurement deviation between the two types of sensors is large and the stability is poor at 0 ℃, and both are better at 20 ℃; the accuracy and stability of measurements from the two types of sensors decrease at low temperature and high temperature. The HMP155A sensor is better and can meet the requirements of operation application.