To address the shortcomings of the control system of conventional squirrel-cage asynchronous wind turbines, this paper proposes a new control method to achieve the research objectives of maximizing their power generation efficiency and minimizing the system cost. The topology of this control method consists of a voltage source converter (VSC), a power factor correction converter (PFCC) and capacitors. It functions by providing excitation for the squirrel-cage generator through the VSC to achieve maximum power point tracking (MPPT) control, and transferring all the active power output from the generator to the DC bus through the PFCC in parallel, so that the VSC only provides reactive power to the generator. The reactive power required by the generator is compensated by capacitors in parallel to reduce the VSC capacity required by the system, thus minimizing the system cost. To improve the efficiency of the system, it is analyzed to settle the slip rate and the optimal capacitor capacity of the system. Based on the theoretical analysis, a simulation verification of the designed control system has been performed based on Matlab software, and the simulation results have proved the feasibility of the design and the effectiveness of the control method.