Machinable plastic drawing mould and manufacturing method thereof

The invention discloses a machinable plastic drawing mould. The machinable plastic drawing mould comprises a substrate which is made of cast steel or cast aluminium and a machinable plastic layer which is arranged on the surface of the substrate; a plurality of dovetail grooves or dovetail ribs which are parallel to each other and are clamped with the plastic layer are formed on the surface of the substrate; and the dovetail ribs or the dovetail grooves which are adapted to the substrate are formed on the surface plastic layer. According to the machinable plastic drawing mould, the dovetail grooves which are buckled with one another are formed between the plastic layer and the substrate, so that the problem of cracking easily caused by adhesive adhesion in the prior art can be solved; and the internal stress produced by thermal expansion can be counteracted through the cooperation between the dovetail grooves and the dovetail ribs, so that cracking is avoided, and meanwhile, the binding strength and the stabi