This paper takes the Ⅱ 1044 fully mechanized working face of Taoyuan Coal Mine as the research background, uses FLAC3D to simulate the working face advancing towards the fault, studies the vertical stress distribution law, the evolution law of the plastic zone, and the slip amount of the fault face when the working face advances to different positions, and formulates scientific and effective fault crossing technical measures and safety measures accordingly. The research shows that when the working face is 40 m away from the fault, the stress at the fault is about 20 MPa, and the plastic zone at the fault has reached the direct bottom. At the same time, a large range of plastic zones appear at the floor and roof of the working face, and the damage is serious. The damage depth of the floor can reach 47.2 m. As the working face moves towards the fault, the fault will be completely destroyed. Therefore, when the working face is 40 m away from the fault, Malisan is injected into the broken roof area of the working face for reinforcement, and cement slurry is injected into the 25-55 supports of the working face for reinforcement. After grouting, the support pressure of the working face is basically stable.