Model of non-parallel light incident multilayer is established. Expressions of film characteristics are given for the case that the incident light beam has a circular cone angle. Numerical experiments are done on the properties of three kinds of typical optical thin films such as multi-cavity filter, non-polarization beam splitter and non-polarization cutoff filter. The results show that as the cone angle of incident light increases, the center wavelength moves to short-wave for the multi-cavity filter, and the transmittance and pass band get worse. The transmittance and waviness increase for both of s and p polarization in non-polarization beam splitter. For non-polarization cutoff filter, the transmittance in pass band shows periodic oscillation, the waviness of s polarization is larger than that of p polarization. There is an increasing trend overall for waviness, in addition the gradient of the transition region is growing.