A mixed method based on FIR and traditional low-pass filter is proposed to fix the warning nuisance in aircraft stall protection device. Combined with longitudinal and lateral aircraft maneuvering characteristic, the signal frequency of attack of angle and lateral acceleration of two important parameters used in stall warning logic is analyzed for the mixed filter design, and then Simulink Filter toolbox is used for the filter design. Simulation results show that the stall warning nuisance can be greatly reduced, especially for the strong background noise,and demonstrated the compliance for the stall warning regulation. The proposed method is not only beneficial to reduce the warning nuisance, but also it is beneficial to solve the similar problems.