The method to eliminate the error of the probe test system for wafer was discussed in this paper. Through analyzing the calibration theory and calculating the calibration model, the known calibration position can be placed on the calibration substrate. By modifying the calibration position of VNA and the signal receiving port, the signals can be extracted and fed back by using the movement of the probe platform and the contact between the probe and the calibration position, and then the error of the probe test system can be corrected.