A linear active disturbance rejection controller (LADRC) was designed to estimate the system unmodeled part and compensate the interference, thereby achieve output power stable when wind speed was above rated wind speed. And the model compensation method was used to optimize the LADRC, to reduce the number of parameters that need to be set and improve system control accuracy. The controller was simulated in three different wind conditions in the 300 kW wind turbines. The simulation results showed that it can quickly adjust the output fluctuation caused by wind velocity variation, made the system output stable and had small overshoot in any wind speed stage. Moreover, the system had good stability and robustness.