Abstract: Under the execrable operating environment，the mechanical sensor for detecting the position and speed signals of the doubly-fed wind power generator leads to more faults and inconvenient maintenance. To solve the problem, a stator flux-based sliding-mode model reference adaptive system (MRAS) speed estimator was proposed. In the proposed sliding-mode MRAS estimator, the stator flux voltage model of the doubly-fed wind power generator was used to obtain the reference model and its current model as the adaptive model, and a slide-mode surface was designed according to the two model output cross product， and the reaching conditions for the sliding mode were analyzed by using the small-signal model. Meanwhile the continuous saturation function is introduced to overcome the high frequency chattering problem. And the performances of the proposed control method were tested in Matlab/SimuLink.