The invention belongs to a device for jetting or pouring liquid or other fluids onto the surface of a workpiece or making the liquid or other fluids flow on the surface of the workpiece and particularly discloses a 
coating device for a plastic plate. The 
coating device comprises a rack and a 
liquid storage pool, and he rack is provided with a lower 
coating roller and an upper coating roller; the rack is provided with a 
liquid storage box; the lower coating roller is provided with a rotating shaft, the end of the rotating shaft is fixedly provided with a rotating rod, and a push rod is hinged to the rotating rod; the 
liquid storage pool is internally provided with a spring and an 
oil supply unit, and the 
oil supply unit comprises an 
oil storage bucket, an oil conveying 
pipe and a 
piston, and one end of the push rod is fixed to the 
piston; one end of the spring is fixed to the bottom of the liquid 
storage pool, and the other end of the spring is fixed to the bottom of the 
oil storage bucket; one end of the oil conveying 
pipe communicates with the 
oil storage bucket, and the other end of the oil conveying 
pipe communicates with the oil storage box; and the oil storage bucket is provided with a first one-way valve, and the oil pipe is provided with a second one-way valve. The device is adopted to performing coating on the plastic plate, the blister 
varnish in the liquid storage box can maintain a certain quantity, manual supplementation is not needed, and the work amount of workers is lowered.