The invention discloses a short-circuit protection device for a power frequency current and lightning surge automatic selection channel and relates to the technical field of lightning protection. The short-circuit protection device comprises a power supply and a power supply lightning arrester. An inlet wire terminal, a splitting or integrating device, a power frequency channel device, a lightning surge channel device and an outlet wire terminal are arranged in a machine casing. The power supply, the inlet wire terminal, the splitting or integrating device, the power frequency channel device, the outlet wire terminal and the power supply lightning arrester are connected in sequence, and the lightning surge channel device is in parallel connection with the power frequency channel device. Front-end protection of the power supply lightning arrester is achieved, the problem that dripping occurs when a power supply line is subjected to lightning hazards is solved, the lightning arrester structure is simplified, the technical requirements for a varistor are reduced, and the short-circuit protection device is suitable for front-end protection of various power supply lightning arresters and short-circuit protection of a main power supply in a frequent lightning area.