The paper proposed a chattering-free full-order terminal sliding mode (TSM) for the doubly-fed induction generator (DFIG) wind power system using the stator magnetic field orientation vector control principle, realizes DFIG active power and reactive power decoupling control. After the decoupling, maximum power point tracking (MPPT) is realized. The method can increase the system robustness and MPPT control, it improves the system fast tracking, stability, and makes wind power generation system capture more wind energy. Finally, the simulation results of controller verify the accuracy and effectiveness of the control strategy proposed in this paper.