Fiber optic gyroscope capable of reducing magnetic field sensitivity

The invention relates to a fiber optic gyroscope capable of reducing magnetic field sensitivity. The fiber optic gyroscope comprises a light source; a detector; a coupler connected with the output optical fiber of the light source to form the output optical fiber of the coupler, and further connected with the tail fiber of the detector; a Y waveguide modulator, which is connected with the coupler and symmetrically splits the output optical fiber of the coupler to form a first tail fiber and a second tail fiber of the Y waveguide modulator; and a polarization maintaining optical fiber coil, which is formed by winding a polarization maintaining optical fiber and is connected with the Y waveguide modulator for respectively crossly welding the first tail fiber and the second tail fiber of the Y waveguide modulator with two input weld joints of the polarization maintaining optical fiber coil with opposite axes. The fiber optic gyroscope provided by the invention greatly improves the inhibition on a Faraday effect, the zero offset performance of the fiber optic gyroscope can be obviously perfected, and the impact of the Faraday effect on the linearity of the scale factor of the fiber optic gyroscope can be obviously alleviated; moreover, an antimagnetic material is not needed, and thus the weight, the size and the production cost of the fiber optic gyroscope are reduced.