The utility model relates to a movable automatic precast beam spraying and maintaining device. The movable automatic precast beam spraying and maintaining device comprises a platform rack, wherein the platform rack comprises a cross beam which is horizontally arranged at a certain height above the ground; two ends of the cross beam are connected to a support leg vertical to the cross beam; the upper end of the support leg is fixedly connected to the cross beam; a roller wheel is arranged at the lower end of the support leg; a walking motor used for driving the roller wheel to walk is arranged on one side of the roller wheel; a guide rail on which the roller wheel walks is arranged under the roller wheel; a plurality of nozzles are arranged in the cross beam and the support leg; a water pump and a control electric box used for controlling the water pump and the walking motor to operate are arranged on the support leg; the water outlet end of the water pump is connected to a water outlet pipe; the water outlet pipe is connected with the nozzles in the cross beam and the support leg; the water inlet end of the water pump is connected to an external water source through a flexible pipe.