An investigation of the temperature dependence of transverse magnetic error in the polarization maintaining fiber optic gyroscope (PM-FOG) with non-skeleton coil is presented. It is found that the transverse magnetic error changes with the temperature, which can result from the temperature dependence of linear birefringence and Verdet constant of polarization maintaining fiber (PMF). Based on Jones matrix method, the relationship between the transverse magnetic error and temperature in PM-FOG is deduced, and the experimental verification is carried out. The experimental results show that for the non-skeleton coil with length of 1 km, radius of 6 cm, linear birefringence of 2027 rad·m -1, and maximum twist rate of 0.382 rad·m -1, the transverse magnetic error changes from 26.51 (°)·h -1 to 30.43 (°)·h -1, under 1 mT transverse magnetic field and the temperature range of -40 ℃ to 60 ℃.