The invention relates to an environment-friendly easily-demolded compression molding device, which comprises an outer mold 1, an assembled polytetrafluoroethylene inner lining 2, an upper cover 3, a lower cover 4, an upper sealing fin 5 and a lower sealing fin 6. The compression molding device is simple and practical in structure, and is convenient to disassemble and assemble; the surface of a molding material is not polluted, the molding material can be used repeatedly, demolding is very smooth, the molding material is smooth and flat on the surface and does not need secondary machining, machining procedures are reduced, and the aims of simplifying demolding post-treatment and improving the economic efficiency and environmental friendliness are fulfilled. When the device is applied to molding equipment for buoyancy materials, the problems of low yield, poor economic efficiency and environmental pollution existing in a buoyancy material molded by using the conventional demolding method are solved.