Given the azimuth transmission errors caused by temperature and electric fields in the non-line-of-sight azimuth transmission system based on polarization-maintaining fibers, we derive azimuth calculation models for polarization-maintaining fibers under the action of a variable temperature and electric field, respectively, from the perspective of the working principle of the non-line-of-sight azimuth transmission system. We also simulate and analyze the influences of the length and thermal expansion coefficient of the polarization-maintaining fibers and the electric field amplitude on the azimuth transmission accuracy. The experimental results show that when the temperature is 20 ℃, the azimuth solution error is not sensitive to temperature, whereas when the temperature is higher than 20 ℃, it is significantly affected by temperature and the length of the polarization-maintaining fibers. The azimuth transmission error can be controlled by adjusting the thermal expansion coefficient and Poisson’s ratio of the polarization-maintaining fibers. The azimuth solution error is affected by both the electric field magnitude and the length of the polarization-maintaining fibers within the electric field. When the action angle is 45°, the electric field amplitude will not produce an azimuth solution error. The conclusion of the study is of guiding significance for studying the environmental adaptability and improving the system measurement accuracy of non-line-of-sight azimuth transmission systems based on polarization-maintaining fibers.