In order to solve the production and transportation problems of large diameter FRP tank, the numerical control winding machine system was developed to realize field winding. The mechanical parts of the system can be conveniently disassembled and assembled in field. Based on the electronic gear control mode the embedded motion controller is adopted to realize synchronous motion control. In this paper, mechanical structure, working principle and manufacturing process are introduced, and winding control model, the function and realization method of control program are analyzed. The application of this system has realized field winding of large diameter FRP tank.