In the phase measurement profilometry, the phase-height mapping is to calibrate the system by the height and phase of several known planes.The four planes method needs the least amount of data,but the height reconstruction of dual-direction mapping method, the more the phase difference is close to 0,the greater the reconstruction height error is.In this article,in order to solve the above problems,a phase-height mapping method based on virtu al reference plane is proposed,that is,by adding a virtual plane with preset height on the basis of the original four planes,the phase distribution of the plane can be obtained by fitting.Then the coefficient tables a、 b、c which are suitable for the whole calibration space are calculate d.Therefore, this problem is solved and the accuracy of 3D shape reconstruction is greatly im proved.The experimental results show that this method can effectively reduce the mapping he ight error.The relative error of the single-direction phase-height mapping method is less tha n 4.76×10－2 mm. The relative error of the virtual reference plane phase height mapping method is less than 7×10－3 mm,and the mean deviation of the plane measurement is less than 5×10－3 mm.