Abstract: Abstract: Accurate calculation of the load in lowering and hauling system during complex terrain rescue is the basis for evaluating security risks and optimize rescue system configuration. Through the mechanical analysis of the typical physical model of lowering and hauling systems in rope rescue, using the capstan equation, the mathematical model of the load of lowering and hauling system under complex terrain conditions was established. Using the mathematical model to analyze the different parts of the lowering and hauling system, optimize the design of the rescue system, improve the safety and efficiency of rescue operations by reducing system load, and avoid the blindness of system configuration.

Key words: Key words: fire and rescue, rope rescue technique, lowering and hauling system, the capstan equation, load model, practical optimization