A wavefront reconstruction method was proposed based on spatial light modulator (SLM) to achieve the requirement of real-time testing of different aspheric surfaces. An interference measurement system based on SLM wavefront reconstruction was designed, in which the computer-generated hologram (CGH) encoding method was chosen according to the intrinsic properties of SLM. To resolve the quality degradation problem of the reconstructed wavefront, a dislocation optimization method was proposed. The process is verified through simulation, and the results showed that the RMS of the reconstructed wavefront was improved by 4.45 times.