The fire-fighting device automatically extinguishes the fire, automatically detects the fire (high temperature), and automatically releases the fire-extinguishing agent, and does not require personnel to operate. In particular, Emperor Yiming’s fire-fighting artifacts are fully submerged to protect closed or semi-enclosed spaces such as power distribution cabinets, distribution boxes, current cabinets, and weak cabinets. The fixed temperature sensing self-starting water-based fire extinguishing device can be arranged in a cable tray, a cable tunnel, a shaft, etc. in a non-closed space. The two fire extinguishing devices complement each other and are simple and convenient to design and install, and do not affect the operation of other equipment and personnel maintenance.