A multi-body dynamic model of the seafloor tracked miner is established by the multi-body dynamic modeling and simulation program RecurDyn/Track,meanwhile the secondary development and integration of the seafloor sediment special mechanical model into the miner’s multi-body dynamic model is achieved. Motion tests of a small scale tracked test vehicle are performed and compared with the simulations of its corresponding secondary multi-body dynamic model to validate the computational correctness of the modeling method. Based on the multi-body discrete element method,and use the platform RecurDyn ProcessNet for secondary development,au automatic parametrical modeling program for establishing a multi-body discrete element dynamic model of the extremely long mining pipeline is compiled by C# language. Integrating the multi-body dynamic model of the seafloor tracked miner and the multi-body discrete element dynamic model of the mining pipeline,an integrated multi-body dynamic model of the total deep ocean mining system is established and its motion simulation is achieved. The spatial motion condition change of each subsystem and interaction forces between subsystems are obtained and analyzed,which can provide references for the total design,performance prediction and operation control of the practical deep ocean mining system.