The invention provides a control method based on slip form extreme searching. The control method is applied to control over a wind power generation system to achieve maximum power tracking. The control method comprises the steps that in the current state detection step, the current power and the current rotation speed of a draught fan are detected; in the parameter matching step, a gain parameter value is matched from a pre-constructed parameter table according to the current power and the current rotation speed; in the maximum power tracking step, the gain parameter value is input into a controller, the gain parameter is optimized by adopting the pre-constructed optimization function according to the pre-determined slip form extreme searching range and the pre-constructed target function, accordingly, the optimal gain parameter value is obtained, and the wind power generation system tracks the maximum power. According to the provided control method, the gain parameter value is matched from the pre-constructed parameter table and then is optimized through the optimization function, the wind power generation system tracks the maximum power, the wind power generation system can be controlled in real time, and the response speed is high.