In this paper,the factors that influence the measurement accuracy of phase measuring profilometry(PMP) based on one frame of deformed pattern are analyzed.Stoilov algorithm with arbitrary phase step is proposed to calculate the phase of the object.It effectively restrains the errors caused by sampling,quantization and rounding during the process of capturing deformed pattern.Compared with the standard N-frame algorithm,only the constant phase shift is necessary by Stoilov algorithm.There is no rigorous requirement for the summation of phase shift.Computer simulation and experiment show that it is feasible and effective to improve the on-line measuring precision of PMP which is based on one frame of deformed pattern.