The current calibration method of pressure parameters of a flight test system is laboratory calibration, which is time-consuming and has the problem that multiple dismounting operations may damage the sensor's interface. In this paper, a field calibration method of pressure parameters is studied, and the in-situ comparison calibration is realized under real working conditions. The characteristic of the magnitude of the standard pressure sensor under the condition of temperature compounding is obtained through experiments, and the temperature compensation model is constructed to realize the accurate acquisition of the standard pressure value. A calibration device consisting of three standard pressure sensors with different ranges, ambient temperature, humidity and atmospheric pressure sensors, and field calibration software was developed. The rationality of the calibration method and device was verified through preliminary experiments. This method can be used as an effective supplement to laboratory calibration, reducing the labor and time cost of calibration and improving the efficiency of flight tests.