Photonic crystal polarization maintaining optical fibers(PC-PMFs) could offer much higher birefringence than conventional PMFs and have many remarkable properties. In this article, the localized function was orthogonalized with another function for the PC-PMFs, so the orthogonal localized functions were got, and the mathematical model of modal birefringence for PC-PMFs was brought forward. What’s more, a mathematical formula of attenuation for PC-PMFs was made, the effecting factors on the attenuation of PC-PMFs were analyzed and the process technologies to decrease the loss of PC-PMFs were also proposed.