According to the problem of temperature drift during pressure test in oil and gas well, the high temperature test in oil well is simulated and the conclusion of temperature drift generating in the process of oil well pressure test is obtained. After perforating, much of heat is released, at the same time, the high-pressure gas pulse is generated in the well and the sensitivity of the sensor has a big uncertainty. Incorporating with downhole environment and temperature drift phenomena from piezoresistive sensors, temperature compensation shall be performed during downhole pressure test so that downhole pressure signals can be measured accurately. Software compensation technologies are used to compensate temperature drift during test process according to experimental data.