Higher calibration accuracy is essential to W-band phased array antennas due to their short wavelength. However, the feed amplitude and phase of the antenna unit usually deviates from its theoretical value because of the production and assembly of the phased array antenna. For this reason, the antennas should be calibrated to guarantee their performance. In order to solve this practical problem, an amplitude and phase calibration method based on the space feed characteristics of T/R modules is proposed in this paper. The proposed method can achieve high-precision alignment of the auxiliary antenna and the center of the tested front, and meanwhile obtain the true amplitude-phase distribution of the W-band phased array antenna. The proposed method effectively realizes the precise beam pointing of the W-band phased array antenna.