The one-step π phase-shifting phase extraction algorithm is presented to achieve dynamic measurement. Two interferograms with π phase-shifting are rearranged to form a spatial-temporal fringe containing time domain and space domain information. This algorithm can solve phase fast by extracting spatial-temporal pattern signal. In frequency spectrum of spatial-temporal fringe pattern, time frequency is introduced in this method, signal spectrum of spatial-temporal pattern is effectively separated from the background interference spectrum, and the signal spectrum can be extracted effectively without high carry frequency. The proposed algorithm is applied in phase-shifting interferometry. Comparing with the traditional phase shifting method, this method can eliminate phase-shifting error and high-frequency noise in test result effectively. In addition, the influence of different frequencies and phase-shifting errors on measurement accuracy is analyzed. The measurement error root mean square of the reconstruction surface can be controlled in 1.358×10-3λ when the normalized spatial frequency is more than 0.03 and phase-shifting error changes within ±30°.