Zinc-alloy with low melting point can be easily sprayed directly on the production surface to fabricate a mould with high precision by arc spraying. But the zinc-alloy mould has the disadvantage of easy invalidation due to its relatively low hardness and poor anti-wear property. In this paper, the surface modification of zinc-alloy tooling by composite electro-brush plating was researched. The joining mechanism between the plating film and sprayed coating was investigated, and the law of quality control on the unification of rapid tooling and surface modification was revealed. A new modification technology possessing the advantage of economical and high quality surface relating to moulding was developed with independent intellectual property right.