The invention relates to a novel mist spraying maintaining trolley. An auxiliary water tank is arranged on one side of the excavation face of a water storage tank. The auxiliary water tank and the water storage tank are connected through a floating ball control valve. The floating ball control valve can adjust the opening and closing degree of the valve according to the water level changes, and automatic water replenishment of the auxiliary water tank is achieved. The interior of the auxiliary water tank is provided with a water pump. The water pump is connected with a main pipeline through awater hose. The auxiliary water tank is internally provided with a heating rod. The back side of the water storage tank is provided with a lower climbing ladder and a control device. The main pipelineis provided with a plurality of atomizing nozzles. A plurality of telescopic assemblies are connected to the positions between an upper arch truss and the main pipeline as well as between a lower arch truss and the main pipeline, the distance between the nozzles and the lining surface can be adjusted. The novel mist spraying maintaining trolley has the beneficial effects that the maintenance efficiency is improved, the labor intensity of workers is relieved, meanwhile, the temperature difference of the water temperature and the curing concrete is reduced, and the maintenance quality is improved.