Aiming at the application of precision length measurement,the error of phase-shifting algorithm based on the cosine dependent algoritm by means of double-beam interference is explored,and the precision formula of intensity distribution of multiple-beam interference(multiple reflection and transmission by the optical surface) with the basic principle of interference optics is derived.

A new error compensating five sample phase shifting algorithm which is insensitive to phase shift error is proposed to retrieve the phase distribution of a fringe pattern.

The results confirmed that the nonlinearity effect would be reduced by increasing of phase-shift number.

This paper gives the theoretical analysis and the computer simulation of this kind of error,and compares the ability of tolerance for detector nonlinearity among N-frame phase shifting algorithms.