A novel demodulation scheme for fiber Bragg grating sensors based on polarization fiber loop mirror is proposed in this paper. The theoretical analysis model is established. The impact characteristics to the demodulation decision from the fabric parameters of the polarization maintaining fiber loop mirror are researched and the numeric value simulation is processed. The beam path system is established. Moreover

the circuit model the software for measuring the parameters and monitoring the demodulation system based on LabVIEW which can eliminate the impact from the fabric parameter error are both designed. The sensor detection experiment is processed and the result is consistent with the theoretical analysis. The system has high stability

high detection precision and strong applicability. It has a very important significance in the application of the fiber grating sensor.