The invention discloses a heat control system in a hydrogen energy storage system and an application and belongs to the technical field of energy conversion and energy storage. The heat control system comprises a hydrogen generation device, a hydrogen storage device and a hydrogen power generation device which are sequentially connected as well as a first cold medium circulating device, a second cold medium circulating device and a third cold medium circulating device, wherein the first cold medium circulating device is used for providing a first cold medium and recovering the first cold medium after heat absorption and connected with the hydrogen production device; the second cold medium circulating device is connected with the hydrogen power generation device; the third cold medium circulating device is used for providing a third cold medium and recovering the third cold medium after heat absorption and connected with the hydrogen storage device; the second cold medium circulating device comprises a first circulating loop and a second circulating loop which are arranged in parallel, a heat source liquid cooling device is arranged on the first circulating loop; a second heat exchanger is arranged on the second circulating loop. The system is high in heat utilization rate and the hydrogen energy storage system is stable.