A rotary laser optoelectronic measurement system is used as part of a multistation network for large-scale metrology. The line-structured laser surface of the transmitter is regarded as an ideal plane for the intersecting measurement. This paper presents how the rotary laser surface model can be optimized for large-scale optoelectronic measurement systems. Initially, the deformation of the laser surface caused by the assembly error in a cylindrical lens is analyzed by Zemax simulation and studied by a visual evaluation method based on a high-precision tri-axis rotary table. Based on the analysis result, the folded linear surface model and the quadric surface model are applied to re-establish the laser surface model respectively to reduce the shape error. A highprecision 3D coordinate field is designed to acquire an accurate surface parametric model and validate the fitness of the new models. The experimental results based on workshop Measurement Positioning System (wMPS) show that both optimization models are conducive to improving the fitting accuracy of laser surfaces, and the quadric surface model fits better when the surface shape is closer to the commonest twofolded linear model. At last, optimizing the laser surface model plays an important role in improving the system measurement accuracy.