In the laser warning system, a non-mechanical scanning Fabry-Perot (F-P) type laser warning method and its crucial component-laser incident sensor design method are brought out, and the F-P etalon with the interferometric filter combination is adopted. For the incident laser pulse with a certain wavelength, the transmittance difference of the interferometric filters is independent with polarization of incident light, and descends almost linearly as the incident angle gets wider. A laser incident angle sensor experimental platform is built up, and the experiment is carried out with a given laser range finder. As the results indicate, when the incident angle is less than 5o, the transmittance difference measured by the laser angle sensor is significantly lower, and the deviation is more than 10%. While the incident angle is greater than 10o, the deviation is reduced significantly. In the laser warning system, a non-mechanical scanning Fabry-Perot (FP) type laser warning method and its crucial component-laser incident sensor design method are brought out, and the FP etalon with the interferometric filter combination are adopted. laser pulse with a certain wavelength, the transmittance difference of the interferometric filters is independent with polarization of incident light, and descends almost linearly as the incident angle gets wider As the results indicate, when the incident angle is less than 5o, the transmittance difference measured by the laser angle sensor is significantly lower, and the deviation is more than 10%. While the incident angle is greater than 10o, the deviation is reduced significantly.