For the problem of receiver flux distribution affected by the mechanical displacements of the dish system, the receiver flux distribution mathematical model is put forward. The system thermal/structural/optical coupled-field mechanism is analyzed and then the influences of different displacement model on the concentrator is identified. Based on the reflect unit as rigid unit, the mechanical displacements is regarded as the mirror unit do the rigid body motion, and the influence matrix of the mechanical displacement to the unit has been deduced. after introducing the surface error, the unit normal vector influence matrix received. Considering the Spatial displacement coordination about the reflector which under the pressure and receiver, Based on the ray tracing method,the multi-field coupling model and the simulation platform was built which combined with Fluent 6.3, ANSYS 12.0 and Matlab 7.0 software. In order to improving the calculating efficiency, the methord of using bounding box to implement the fast collision detection has been putforward, and found that using Multistage cone surface to fitted the pipe surface can also improve the solution speed. Based on the 38 kW dish system, the simulation platform was built,and the influence of the typical working condition of wind load and the tracking error on the flow distribution has been analyzed. The result proved the validity of the simulation platform and present a reference for the comprehensive optimization of the dish system.