Abstract: Polarizer is one of the important polarized components of reflecting fiber-optic current transducer, but the impact of its imperfection has not been presented so far. This paper studied the polarizer independently provided that the rest devices were ideal. Then Jones matrix was employed to establish the matrix expression of every device and the expression of interference results of the imperfect polarizer was derived. The influence of extinction ratio and the pigtail splice point of the polarizer on reflecting fiber-optic current transducer was analyzed and the simulation was carried out. The result indicated that in the closed-loop process, the polarizer with an appropriate parameter and a fine fusion splicing of the pigtail could reduce the impact of the imperfection of polarizer on the whole system. This study can be used for the analysis of light path error and the improvement of transducer structure.