With the increase in demand for metal resources, research on deep-sea polymetallic nodule mining has been reinvigorated, but the problem of its environmental impact cannot be ignored. No matter what method is used for mining, it will disturb the surface sediments of the seabed, thereby increasing the concentration of suspended solid particles and metal ions in the water body, changing the properties of the near-bottom water body and sediments, and affecting biological activity and the living environment. Focusing on the ecological and environmental impacts of deep-sea polymetallic nodule mining, taking as our main subject of focus the dynamic changes in sediments, we investigated the environmental impacts of nodule mining and their relationships with each other. On this basis, certain understandings are summarized relating to the ecological and environmental impacts of deep-sea polymetallic nodule mining, based on changes in the engineering geological properties of sediment, and solutions for current research problems are proposed.