The transmission spectrum characteristic of two-segment polarization maintaining fibers Sagnac interferometer was investigated and simulated in detail and the optimal parameters for eliminating the crosstalk between the two polarization maintaining fibers was obtained. A temperature-insensitive pressure sensing technology was proposed. An experimental Sagnac interferometer was built and the solid core polarization maintaining photonic crystal fibers were taken as the sensing probe. The side pressure sensitive coefficients and the temperature crosstalk drift were measured and compared. The experimental results show that the side pressure sensitive coefficient was about 0.287 7 nm/N and the temperature drift was less than 0.1 pm/℃.