The invention provides a process for forming a Zn-Sn
alloy layer through
mechanical plating and Sn reduction disposition. The process comprises the steps of workpiece pretreatment before plating, establishment of a base layer on the surface of the workpiece, and alloyed plating thickening. A compound surfactant is used to change the characteristic of a plating solution, thus an environment in which continuous deposition of
metal Zn
powder on the surface of a plated part can be ensured, adsorption deposition plays a main role, and reduction carrying deposition plays an auxiliary role can be formed; a reduction deposition activator prepared by mixing a stannous salt, a
ferrous salt, an
ammonium salt,
phosphoric acid and water is used for supplying
Si element for the Zn-Sn plating layer through
mechanical plating. The plating is smooth, bright, good in uniformity and high in compactness. As no
metal Sn
powder is adopted, carrying deposition of crude and large particles can be avoided, the reduced Sn atoms are preferentially adsorbed on the Zn
powder and Zn powder alga-gobbets while the size of the Sn atoms is far less than that of the Zn powder and Zn powder alga-gobbets, under the same movement and
impact conditions, the layer formation conditions of the plating are changed toward the direction favor of compaction and leveling, the
utilization rate of non-
ferrous metal is beneficial to being improved, and the production cost is lowered.