The phase error caused by intensity saturation in the projection grating phase-shifting profilometry is studied.The applicability ranges of phase-recovering algorithms corresponding to different intensity saturation coefficients of N frame phase-shifting technique are studied.The formula of the phase-recovering algorithm corresponding to seven-frame phase-shifting method is deduced.The theoretical analysis indicates that the applicability range of the phase-recovering algorithm will be extended with the increasing of phase-shifting steps.Finally，some Simulative and experimental results are presented to prove the availability of the phase-recovering algorithm.The phase error caused by the image intensity saturation can be effectively decreased by the phase-recovering algorithm based on seven-step phase-shifting technique.