The change of the equivalent refractive index of liquid crystal molecules in liquid crystal spatial light modulators has been used to achieve dynamic control of optical wavefronts, thus realizing zero position interference measurements of optical aspheric surfaces. However, the pixel pitch, filling ratio of the cell structure, and gray-level number directly affect the accuracy of wavefront control. This study is based on Fresnel diffraction theory and the discrete Fourier transform algorithm.The physical light field was analyzed using a numerical analysis software,VirtualLabTM.The influence of pixel-independent units on the reconstruction compensation wavefront precision of the liquid crystal spatial light modulator was investigated, and a simulation model of the wavefront propagating through the spatial light modulator to the surface to be measured was established.The theoretical algorithm's background error of wavefront reconstruction caused by the pixel structure factor was evaluated, and the multifactor coupling error of the image structure was determined by focusing on the sampling frequency of pixel size and the maximum space of thewavefront.For the frequency matching problem, a spatial light modulator was selected to meet the requirements of high-precision measurement according to the theoretical model of the reconstructed wavefront, thereby effectively reducing the cost of the dynamic detection system. Theoretical calculation shows that the factors that restrict the spatial light modulator in reconstructing the high-precision wavefront (root mean square error of 0.01λ) are closely related to the nonlinearity of the liquid crystal molecular response and the inconsistency of the substrate space.