Aiming at the problem of low pulse rate measurement accuracy of photoplethysmography in low perfusion，by analyzing the characteristics of FFT amplitude and phase difference，a pulse rate measurement method based on amplitude and phase difference criterion by using Rife algorithm is proposed. This method is based on the robustness of the Rife algorithm in the adjacent frequency center area，and uses a new criterion to process the frequency shift of the signal，so as to obtain a higher pulse rate measurement accuracy. The established pulse wave model is simulated，and the results show that under the condition of signal-to-noise ratio of -14 dB，the performance of the proposed method is equivalent to that of the I-Rife algorithm，and the correction direction misjudgment rate is reduced by about 15% compared with the Rife algorithm. Under the condition that the number of points is in the order of magnitude，the proposed method reduces the calculation amount by more than 25% compared with the I-Rife algorithm. At the same time，the pulse wave signal is used for experiments，and the results show that the proposed method has high measurement accuracy and stability. The new measurement method has higher measurement accuracy and provides a new way of thinking for the measurement of human pulse rate.