The invention provides a wind energy converting system sliding mode control method and device based on a T-S fuzzy model. To solve the problem of the fault of an actuator in a wind energy converting system, the T-S fuzzy model is utilized for describing a nonlinear wind energy converting system with uncertain actuator fault information, the approximation accuracy of a controlled object is improved, and a good model foundation is established for sliding mode control. Meanwhile, by means of a sliding mode controller designed based on the linear matrix inequality technology, the stability of the wind energy converting system is guaranteed, and the robustness and fault tolerance of the wind energy converting system are improved. The precise tracking of the rotating speed of a power generator and the electromagnetic torque can be achieved when the uncertain actuator fault exists in the wind energy converting system, and the maximum wind energy capturing of the wind speed below the rated value is achieved, and a valuable reference scheme is provided for efficient and stable running of the wind converting system.