Abstract: In this paper, it puts forward a new design method which is oriented to the multi-functional products based on the three existing extension design methods with synthesization and refinement. Furthermore, it proves that the method of designing multifunctional products is feasible and effective, illustrated by a casemulti-functional dryer. The method of designing multi-functional products is the development and enrichment of the three existing ones of extension engineering methods. It provides a set of systematic design steps for the development of designing multi-functional products and effectively solves the contradictory problems in the design process so as to shorten the design cycle.

Key words: methods of extension design； multifunctional product creation method； multifunctional dryer； content matter restructuring