In the paper, we gave a phase contrast method to measure the birefringent axis orientation in polarization-maintaining fiber (PMF) with matching refractive-index (MRI). The phase contrast intensity profiles in PANDA fiber and distinguishing characteristics were obtained by image analysis of side view image systems. Experiments and computer simulation showed that the difference between two crests of intensity profile was not only used for determining angular orientation but also for determining the direction of rotation. The angular resolution of orientation was less than 2 degrees in phase contrast method. The difference between geometric and birefringent axes in PMF would be the limit of accuracy in side view image system.