The utility model discloses a tunnel secondary lining maintenance device convenient to disassemble, assemble and replace. Water supply main pipe, a universal joint is communicated in the middle of thewater supply main pipe; the universal joint is communicated with the water supply branch pipe and the automatic timing valve through a plastic hose; a drainage pipe is further installed on the watersupply branch pipe, a plurality of connectors communicated with the drainage pipe are arranged on the drainage pipe, an automatic rotating water device is installed on each connector, and the maintenance device is installed and fixed on a tunnel secondary lining through matching of a plurality of fixed installation parts and a plurality of embedded parts. The watering device is convenient to use,a user does not need to hold a water pipe by hand to conduct watering operation, high-altitude operation is avoided, and safety is guaranteed; the uniformly distributed spray heads are adopted for watering, so that a good water-saving effect is achieved, the electronic timer and the automatic timing valve are designed for setting reminding control, the watering time is determined, automatic watercut-off is achieved, the automation degree of watering operation is greatly improved, the labor intensity of workers is reduced, and the cost is saved.