Polarization-maintaining fiber coil is the core component of polarization-maintaining Fiber Optic Gyroscope（FOG）. The second-order polarization crosstalk occurs within the polarization-maintaining fiber coil of the polarized light will produce many second order interference terms in the interference output end of the FOG

which may introduce phase error and affect the static parameters of the FOG

such as zero-bias stability. In this paper

we design a set of experimental fixture to produces high crosstalk points by exert precision pressure on the polarization-maintaining fiber coil. By controlling the two fixtures exert pressure in polarization-maintaining fibers depolarize length to produce a large number of second order crosstalk

the crosstalk points data is extracted for simulation calculation. Compared with the zero-bias stability data obtained from the actual test

the theoretical simulation value is consistent with the actual test value. As the pressure increases the intensity of the second-order crosstalk

zero bias stability of the FOG is worsening. The maximum intensity of second-order crosstalk produced by pressure is compared with that without pressure. The experimental results show that the zero bias stability of coil 1 is deteriorated from 0.006 3°/h to 0.015 1°/h

and zero bias stability of coil 2 is deteriorated from 0.012 5°/h to 0.017 1°/h.