ing at the status that the scanning laser surface of transmitter in the model of workshop measurement positioning system (wMPS) is regarded as an ideal plane, a kind method of the visual evaluation of laser surface is proposed based on a high-precision rotary table. On basis of the evaluation results, a linear folding judgment mechanism is introduced, and the mathematical model of wMPS scanning laser surface is optimized and reconstructed to reduce the systematic errors in the intersection measurement model. The new model is evaluated by the large-scale high-precision coordinate field. The results show that the new wMPS scanning laser surface model has a better effect in the fitting of an actual laser surface, and it is helpful to improve the measuring accuracy of wMPS.