The phase-shifting interferometry technique is widely used in wavefront detection interferometers due to its high measurement accuracy. The phase shift error is the main source of error in measurement process. Based on a self-tuning phase-shifting interference algorithm, the accuracy of wavefront phase restoration is studied under calibration errors and random phase shift errors. For the calibration error, the algorithm can accurately calculate the actual phase shift step size,thus greatly improving the phase restoration accuracy.Compared with the classic five-step Hariharan algorithm, the simulation results show that the phase restoration PV (Peak-Valley) and RMS (Root Mean Square) error response of this algorithm is lower, and its PV error response is much lower than 10-3λ, where λ is the center wavelength of the light source, while the Hariharan algorithm is on the order of 10-3λ. Based on the phase solving process of the self-tuning algorithm in phase shift calibration error, the algorithm is extended to be more suitable for random phase shift error. Within the same 20% random phase shift error range, the absolute value of the deviation from the Hariharan algorithm calculation result is close to 10-9λ, which can achieve high restoration accuracy. The self-tuning algorithm is used in the measurement of the surface topography by the interferometer. The experimental results show that compared with the Hariharan algorithm, the self-tuning algorithm can obviously suppress the ripple error when there is only calibration error. There is a deviation in the surface PV. In a small vibration environment, the phase restored by the two algorithms are highly consistent.