Coating gasket, coating machine and pole piece coating process

The invention provides a coating gasket which is an equal-wall thickness integrated sheet and is generally a frame shaped like a Chinese character 'ri', two openings are formed in the frame, the two openings are symmetrically distributed at the two sides of the end of a partition part inside the frame shaped like the Chinese character 'ri', the partition part includes an outer end provided with achamfer, the frame shaped like the Chinese character 'ri' includes the outer end provided with the chamfer, the two openings are symmetrically expanded from inside to outside to the two sides, the expand angle is 110-180 degrees, the expansion length is 3-8 mm, and the thickness of the gasket is greater than 1.0 mm. Through the micro-expanded openings, sprayed slurry is diffused to the two sides,the thickness of the edge region is much smaller than that of the intermediate region, and the bulging phenomenon existing in a coating process with the surface density higher than 450 g/m<2> is avoided; and the thickness of the gasket is increased, the problems that due to the high surface density forming requirement, the cavity pressure needed by an existing 1 mm-thickness gasket is large, and consequently the surface density is unstable, and the dressing width becomes large are solved.