The invention provides a safe cooling device for molten salt. According to the invention, an integrated crucible cover is placed on a crucible; a sealing gasket is arranged between the integrated crucible cover and the crucible; the integrated crucible cover comprises an inner baffle plate, an outer baffle plate, an outer heat exchange element welding hole and a salt inlet hole; an outer heat exchange element is welded on the integrated crucible cover and vertically inserted into the crucible; the upper part of the inner heat exchange element is connected with a water tank, and the lower partof the inner heat exchange element is inserted into the outer heat exchange element; and a water tank communicates with the atmosphere. The safe cooling device of the invention adopts the integrated crucible cover with the baffle plate and a drainage pipeline and employs a double-layer heat exchange element structure, so the safe cooling device can effectively reduce the risk of explosion caused by direct contact between cooling water and high-temperature molten salt due to partial damage of the heat exchange elements in an accident, greatly improves the safety factor of a system, ensures thesafe cooling of the molten salt, and meets the design requirements of passive safety system. The safe cooling device operates at atmospheric pressure, has low requirements on pressure resistance, reduces designing and manufacturing cost, and is reasonable in design, ingenious in structure, simple and practical to use, easy to assemble and mature in technology.