The field of view of the laser warning system is an important target of its performance quality. The laser spectrum based on the non-scanning Fourier transformation interferometer in the experiment foundation is imsestigated,The path difference function about the incident angle and the coherent position′s is calculated for any angle laser incidences in the field of view in 60°. The two non-scanning Fourier transformation interferometers method is proposed to solve under the vertical angle. According to the simulation experimention,it is found that the interference fringes changes dense,bright band thinning,and wavelength faraway when the incident angle′s changes. The experiment proves that the interference fringe computation and the simulation result is coincident,the laser warning system may detect the laser spectrum information effectively in the wide field of view,and the highest precision of laser incidence direction may reach 1°.