Abstract: It is well known that the temperature drifts limit the accuracy of the high temperature and pressure gauge (HTPG). In this paper,a high temperature and pressure calibration system was designed which is consist of piston manometer,high and low temperature box and pressure transmitting devices. The data collection of pressure gauge,calibration curve fitting,automatic calculation,error analysis and report printing can be accomplished by the system computer. The introduction of temperature drift correction has greatly improved the accuracy of the HTPG,which is an important basis for promoting the wide application of this kind of system.