The detection of crane braking descent distance faces numerous challenges in practical engineering applications, primarily due to limitations in the measurement accuracy of existing detection equipment, the complexity of on?site operations, and high equipment costs. A method is proposed to obtain the braking descent distance by using inertial sensors to collect acceleration and angular velocity data during the crane braking process, performing attitude calculation, and combining it with a double integration algorithm. First, a Lagrangian dynamic model of the crane is established to analyze the coupling relationship between the braking descent distance and the equipment environment. Second, a data acquisition device is designed, the detection steps are described, and data synchronous transmission is employed to enhance signal reliability. Finally, the data processing method is investigated, a complete data processing workflow is designed, complex integration algorithms are compared and analyzed, and practical feasibility is verified. The results indicate that this detection method can prevent serious accidents such as load dropping caused by insufficient braking performance, offering superior comprehensive performance, strong feasibility, and promising market prospects.