The invention provides a concrete block curing device. The concrete block curing device comprises a box body with the front provided with an opening, the inner walls of the upper end and the lower end of the front opening of the box body are fixedly provided with two parallel guide rails correspondingly, and two vertical sliding doors are movably installed between the two guide rails; the top of the box body is fixedly provided with a water tank, the water tank is internally and fixedly provided with a plurality of partition plates, the partition plates partition the box body into a plurality of cavities, each cavity is internally provided with a placement box with the top provided with an opening, the bottom of the rear end of each placement box is provided with a water outlet, and each water outlet is fixedly connected with one end of a second water discharging pipe with a valve; an outlet of the water tank is fixedly connected with a plurality of pipes, one end of each pipe is provided with an electromagnetic valve, the water discharging end of each pipe is fixedly connected with one end of a fixing block, and the other end of each fixing block is fixedly provided with a first water discharging pipe and an air feeding pipe; and each pipe is correspondingly connected with one cavity. When the placement boxes are used, the electromagnetic valves on the corresponding pipes can be switched on, the placement boxes in use are cured and processed, and thus resource waste is avoided.