The deep-seabed mining system for mining resources consists of a mining vessel, lifting riser, lifting pump, buffer system, flexible riser, and mining robot. Because this system is exposed to extreme environments such as fluid resistance, high water pressure, and deep water, a considerable amount of time and cost is consumed in the design and test evaluation of equipment. To tackle these problems, the deep-seabed mining system in an extreme environment requires simulation-based technology. In particular, due to the large movement caused by marine energy, vibration caused by the operation of the mechanical system, and driving resistance of mining robot by the subsea soft soil, it is very important in the mining system design to analyze the dynamic effects of the various elements that constitute the deep-seabed mining system in a single integrated environment. This paper introduces the development of an integrated dynamic simulation method for deep-seabed mining systems and discusses the results.