The invention relates to a gasket for welding and fixing a waterproof board and a material for producing the same. The plastic gasket comprises a gasket body; a blind hole is formed in the center of the gasket body; an insertion hole is formed at the bottom of the blind hole, wherein the end face where the blind hole is formed is an inclined plane or a cambered surface, so that a cone frustum shaped structure is generally formed on the section of the gasket body. The plastic gasket is prepared from the following components in parts by weight: 80 to 95 parts of low density polyethylene, 5 to 20 parts of thermoplastic elastomer, 0 to 2 parts of colorant and 0 to 0.5 part of antioxidant. The gasket disclosed by the invention overcomes the defects that an existing gasket is difficult for forming an effective welding face, and the gasket is easy to pull out. After the gasket disclosed by the invention is welded, the gasket is difficult to separate from the waterproof board, and under the tearing action of an external force, a coiled material is difficult to damage.