Abstract: The common method of the design methodology is used as scheme of friction-wear tester, it is scientific and effective for determining the design programme. The practical application of design methodology was illustrated using design example of a friction-wear tester in this paper. Taking the form of with example, it introduced the implement method of each major step in detail , demand items table-functional analysis-building up the design model box-programme selection-programme evaluation.Among them, the key lies in the functional analysis, building up the design model box and programme evaluasion