To meet requirements on product, a new assembly variant design methodology based on parameterization was proposed. The principle of assembly variant design based on parameterization was researched. The parametric model of part was established. The parameter of part was analyzed. A new product information model was established according to the mating relationship type among constituent parts of assembly. Taking SolidWorks as a 3D environment and VC++ as a development tool, a variant design system was developed for assembly, variant design of assembly was realized. Finally, an example of garbage crusher is given to verify the feasibility of the method.