Abstract: In the field of coal mining, the traditional automatic top cutting pressure relief process without coal pillars faces a series of challenges. The safety of the operators in the bi-directional energy gathering blasting pre splitting top cutting process and high-pressure water top cutting process is difficult to guarantee, the manual labor intensity is huge, and the process is complex and cumbersome. In order to overcome these bottlenecks, China Railway Construction Heavy Industry Group has developed a mining chain arm cutting machine, which replaces the traditional manual cutting process and greatly improves the safety and efficiency of operations. In order to ensure its safety and reliability under complex working conditions, simulating and analyzing the stress distribution, deformation, and dynamic response of the chain arm under actual working conditions can optimize design, improve operational efficiency, reduce costs, achieve fault prediction and health management, thereby improving overall construction quality and operational efficiency. This has important theoretical and engineering significance for promoting the progress of related engineering technologies. This paper analyzes the stress and displacement of the chain arm of the mining top cutting machine under specific working conditions. The numerical simulation of the cutter disk and tools of the mining top cutting machine chain arm is carried out, and the stress and displacement of the chain arm structure at a cutting depth of 7 meters are analyzed in detail to ensure the stability and reliability of the structure. The cutter material is 50Mn2V and thetool material is 40Cr. The chain arm composed of the two can meet the strength requirements at a cutting depth of 7 meters. After strict numerical simulation verification, the durability and efficiency of the equipment are further guaranteed. On site application is carried out in 42204 auxiliary transportation lane, and the effect of top cutting pressure relief is ideal, achieving complete collapse of the roof along the cutting seam and greatly improving the effect of top cutting pressure relief. In addition, the design of the equipment takes into account the complexity of the underground environment, using tracked movement and low-speed planning technology, and a grease lubrication cooling system to ensure safe application in high gas mines. The results of this study not only improve the performance of top cutting machines and promote the development of top cutting machine technology, but also provide strong technical support for coal mine safety production, indicating a positive transformation in the direction of coal mine mining process automation.