Abstract: Since buoyancy materials for submersibles often suffer from problems such as denting and cracking during the marine environmental tests after being coated with protective coatings, the all-round hydrostatic pressure resistance of buoyancy materials coated with different kinds of coatings is investigated. The results show that the type of coating has a small effect on the material. After wrapped the coating, the hydrostatic pressure resistance of the material decreases and the depth of the water used becomes shallower. The damage mechanism of the solid buoyancy materials with protective coatings under hydrostatic pressure is proposed.