Abstract: In the movement of the multi joint swivel arm,the deep-sea mining mechanism is affected by the hydrodynamic force of the ocean, which in turns affects the driving torque of the arm and the driving force of the luffing mechanism. This paper analyzes the influence of the hydrodynamic force on the deep-sea mining mechanism, with a dynamic model of the mining arm in its capacity of adjusting the mining attitude. As an example of a mining mechanism of a specific arm size, we obtain the variation curve of the driving force of the joint driving torque and the variable amplitude mechanism oil cylinder against time, and the change curve of the joint driving torque based on the ADMAS model. By means of the dynamic numerical solution and the simulation analysis of the mining boom, the dynamic equation is verified.