The utility model discloses a battery case coating machine's diolame device, including hanging membrane support, sliding plate, horizontal anomalous movement cylinder, hang be equipped with on the membrane support around the horizontal slide rail, horizontal slip around the horizontal slide rail around horizontal anomalous movement cylinder drive sliding plate is followed, the sliding plate is equipped with the battery case in proper order along the fore -and -aft direction and snatchs structure, film feeding device, film shutdown mechanism, is equipped with the film and presss from both sides the membrane device below film feeding device. The utility model discloses a battery case diolame device existing battery case diolame equipment on for market, the structure is simpler, moves more reliably, and the cost is also cheap relatively moreover.