The invention discloses a low-cost power generation system control method. According to the low-cost power generation system control method, a high-frequency signal is injected into Park inverse transformation to obtain a q-axis high-frequency current response value with rotor position signal information, after processing the signal, an estimated value of the generator rotor position signal can be easily obtained without a position sensor, and accordingly the cost is lowered, and the volume is reduced; a fuzzy PI regulator replaces a traditional voltage PI regulator in the voltage regulation, the self-adapting ability and disturbance rejection ability of the generator are improved, and the emitted voltage is more stable; a predicting controller replaces a traditional current PI controller in the current regulation, the hysteresis characteristic of the traditional current PI controller is solved, and the band width and dynamic performance of the power generation system are improved; an SVM is combined with a four-legged converter to improve the system reliability, and the power generation system still can generate power normally when the generator breaks down.