The utility model discloses a maintenance-free arrester for the catenary of high-voltage apparatus, the technical problem is that an arrester for the catenary of DC electrified railway is operated without maintenance. The technical solutions are adopted as follows: the utility model comprises an arrester body and an isolation insulator. The arrester is provided with an isolating device for isolating the high voltage of power grid from the arrester when the short trouble of the arrester body and atmosphere over-voltage of the catenary are happened. Compared with the prior art, after the arrester body happens deterioration or short trouble, the fault arrestor body is isolated from the catenary so as to ensure the normal power supply for the catenary; thereby the arrester can be operated in the catenary of DC electrified railway without maintenance, and the reliability of the power supply for the catenary is improved, and the maintenance workload and related costs are reduced significantly. The utility model is applicable for the catenary of DC electrified railway.