An active disturbance rejection attitude controller was designed to control its attitude based on the nonlinear and coupled model of small quadrotor aircraft.The active disturbances rejection attitude control technique was introduced and the structure of the active disturbance rejection controller was described including the arranging transitional process extended state observer and nonlinear law state error feedback.Simulation was carried out based on Simulink.The parameter tuning and simulation results indicate that the designed controller has strong robustness and anti-disturbance performance and the system has good dynamic performance and steady state performance which can control the nonlinear and coupled system effectively.