Coded structured light can rapidly acquire the shape of unknown surfaces by projecting suitable patterns onto a measuring surface and grabbing distorted patterns with a camera. By analyzing the deformation patterns appearing in the images, depth information of the surface can be calculated. This paper presents a new concise and efficient mathematical model for coded structured light measurement system to obtain depth information. The interrelations among model parameters and errors of depth information are investigated. Based on the system geometric structure, the results of system parameters affecting object imaging can be obtained. Also, the dynamic deformation patterns can be captured under different measurement conditions. By analyzing the system parameters and depth information errors, the system constraint conditions can be determined, and the system model simulation and error analysis are discussed in experiments, too. Also, the system model based on optimal parameters is utilized to implement reconstruction for two objects.