The separation between s- and p-polarization components is an invariable effect in thin film edge filters used for tilted incidence. So it is difficult for many applications, especially for optical communication. A novel design method is put forward and the cutoff filters with depolarization at incidence angle of 45° are achieved. The polarization separation at transmittance 50% for a long-wave-pass filter and a short-wave-pass filter is 0.3 nm and 0.1 nm respectively. The design method is based on a broad band Fabry-Pérot thin film interference filter in which higher or lower interference band in both sides of main transmittance peak can be used for an initial design of long-wave-pass filter or short-wave-pass filter and then can be refined to reduce the transmittance rippers. The spacer 2H2L2H or 2L2H2L of the interference filter is usually taken. Moreover, the method for expanding bandwidth of rejection and transmission is explained. The bandwidth of 200 nm for both rejection region and transmission band is obtained at wavelength 1550 nm. In this way, the long-wave-pass and short-wave-pass edge filters with zero separation between two polarization components can easily be gotten and fabricated.