The establishment of deployment spare parts package is of great significance to the support of combat aviation materials of our army. The primary problem is to determine the variety, this paper puts forward the logical decision diagram and principal component analysis method. From the 10 factors of criticality,replaceability, life control, combat damage, reliability, universality, redundant structure, consumption, economy and financing,through the comprehensive analysis of aviation materials and maintenance, the score and ranking of spare parts are calculated, the rationality of this method is verified by an example, and a scientific method for determining the variety of spare parts package is put forward.