To ease the polarization fading phenomenon of weak fiber Bragg grating array, the influence of the polarization variation of the light pulses induced by the birefringence effect on the interference intensity is analyzed theoretically, and the coupling coefficient of the alternating item is found to cause the distortion of phase signal, which is demodulated by the zero difference symmetry algorithm. In order to reduce the impact of the polarization fading phenomenon, we propose a kind of polarization compensation method based on real-time polarization measurement, by which the coupling coefficient of the alternating item is eliminated. The simulation results show that the polarization compensated zero difference symmetry algorithm can achieve stable demodulation results in a large dynamic range, and solve the large-range jump problem of the signals in the demodulation process of the conventional zero difference symmetric algorithm.