Abstract: The computational complexity of traditional Phase Calibration extraction method based on correlation increased greatly with the increasing of PCAL signals’ number. An efficient PCAL signals extraction method based on DFT was proposed. According to the equal frequency interval characteristics of PCAL signals, all of the phases of PCAL signals can be obtained by one time DFT computation. The efficiency of the new method has obvious superiority with the increasing of PCAL numbers. The root mean square error (RMSE) formula of phase estimation was derived among (single PCAL signal power to noise power spectral destiny ratio), integration time, PCAL frequency interval, quantization bits, and interference with the same frequency, under Gaussian white noise. The RMSE formula is found to be effective by Monte Carlo simulation.