The invention relates to the technical field of energy storage, and provides a protective device for a high-temperature heat storage system. The device comprises a flow guide pipe and a protective shed used for covering the high-temperature heat storage system, the bottom end of the flow guide pipe is fixed on the ground in the protective shed, and the top end of the flow guide pipe extends out ofthe protective shed; and a flow guide port is formed in the flow guide pipe, the flow guide port is located in the top surface, close to the protective shed, of the protective shed, and an air inletis formed in the lower part of the protective shed. According to the device, the structure is simple, and installation is convenient; and the protective device covers the high-temperature heat storagesystem, inherent leakage heat of the high-temperature heat storage system can be used for driving the leaked oil gas to be continuously discharged out of the protective shed through the flow guide pipe, so that the low-boiling-point oil gas gathered near the high-temperature heat storage system is removed in real time, an explosion accident is avoided, the driving part is not needed as well, theservice life is prolonged, and the cost is reduced.