The invention discloses a high-precision steel plate spraying device. The spraying device comprises a fixed base, a supporting block and a fixed block, wherein the supporting block and the fixed blockare located on the upper end face of the fixed base, the fixed block is internally provided with a moving cavity with a leftward opening, the right end wall of the moving cavity is rotatably connected with 12 rotating shafts, a spraying block is arranged in the moving cavity, the rotating shaft is provided with a rotating wheel for driving the spraying block to move, the rear end wall of the moving cavity is provided with a moving spring enabling the spraying block to be reset, five spraying openings for spraying paint are formed in the spraying block, and control switches are arranged in thespraying openings. During work, through precise current control of the electromagnetic blocks, the shielding area of a shielding plate for a steel plate is controlled, the spraying area of the steelplate is precisely controlled, the control precision is improved, through mechanical transmission, the steel plate spraying can be continuously carried out, and the steel plate spraying work efficiency is improved.