On the basis of analyzing the principles of interleaver filters of the interference of polarized light and planar lightwave circuit-type lattice structure, the equivalent mathematical representation of the spectral transmittance of the two kinds of interlearers is revealed. The equivalent relationships of the structural parameters of them are given. The interleaver filter baged on planar lightwave circuit-type lattice structure can be designed through directly utlizing the structure parameters of crystal obtained by the method of companing Fourier series. A two-stage lattice structural interleaver filter is designed by the use of the method. Compared with only one group of structural parameters obtained using a lattice theory proposed recently, the designing method is more simple and efficient for isolation to be increased by 5 dB and many groups of structural parameters to be obtained.