The invention discloses an exposure machine for printing. The exposure machine comprises a cabinet body, ultraviolet lamps, a vacuum pump and a sealing cover for covering the cabinet body, a pipelineis provided with a unidirectional-gas discharging one-way valve, the machine also comprises an exposure plate part, a driving part and a control part, the exposure plate part includes four slide plates, slide seats, gas suction members and exposure plate units, one ends of the slide plates are slidably connected to the sidewall of the cabinet body, and the gas suction parts are slidably connectedto the slide seat through springs; the driving part includes a power source, telescopic rods and a driving part, the driving part is connected to the telescopic rods and is used for driving the gas suction members to move, and the telescopic rods are provided with the ultraviolet lamps; and the control part comprises a controller, pressure sensors and first electronic control valves, the gas suction members are provided with gas discharging tubes, the first electric control valves are arranged on the gas discharging tubes, and the power source, the pressure sensors and the first electric control valves are respectively electrically connected with the controller. The exposure machine can ensure the uniformity of an exposure plate, and can avoid generated harmful gases from escaping in orderto ensure the health of operators.