Abstract: Some concepts of the generalized satisfactory degree are defined and characterized, and the multi-objective optimization theory based on the generalized satisfactory degree theory is explored. Aimed at the no-rationality of the single optimization design of the working unit of the loader, after the analysis of its design requirement, the satisfactory optimization design is developed. It is shown that this method not only can improve the quality of the design, but also can represent the requirement of the designer and user much more. It provides a new approach to the design of the working unit of the loader and other mechanical design.

Key words: Mechanical design, Satisfactory degree, Satisfactory optimization, Working unit of loader