In order to solve the problem of high precision measurement of grating pitch in three-dimensional grating measurement

an adaptive three-dimensional object grating pitch measurement method is presented in this paper.Its implementation processes are as follows:obtain the object outline based on a large pitch grating;according to the achieve outline

divide the target area by non-Unicom zoning laws;adjust the partition grating pitch and take second projection;according to the divided target area

reconstruct the three-dimensional object to achieve high-precision measurement regionally.The simulation results show that compared to the traditional four-step phase shift method

the measurement accuracy of the proposed method（with the adaptive grating pitch）is increased by 6.78%

indicating that the proposed method can achieve the three-dimensional object measurement more accurately

which also has good practical value.