The invention relates to a movable automatic spray maintaining device for prefabricated T-shaped beams. The movable automatic spray maintaining device comprises vertical steel pipes, a transverse steel pipe, a relay, a pressurization pump and a circulation water tank. The vertical threaded steel pipes are multi-segment steel pipes. The transverse steel pipe is an equally-spaced segmented steel pipe. Tee joints are connected between segments of the transverse steel pipe and are further connected with the vertical steel pipes. One end of each vertical steel pipe is connected with a connector of an atomization faucet. A detachable end cap is arranged at one end of the transverse steel pipe. The other end of the transverse steel pipe is connected with one end of a rubber pipe through a connection pipe. The other end of the rubber pipe is connected to the circulation water tank. The relay and the pressurization pump are further connected to the rubber pipe and located between the connection pipe and the circulation water tank. According to the movable automatic spray maintaining device for the prefabricated T-shaped beams, the height of the atomization faucets and the size of the spray maintaining area can be adjusted, cooperation of machines like gantry cranes does not need to be used, and moving, segmenting or assembling can be manually conducted.