Abstract: Based on the research and practical experience for many years,the use and develop- ment of the multivariate statistical analysis theory in the multiparameter flight measured data are introduced in this paper.Using average error method,k-average value method,minimum dis- tance method and Isodata method comprehensively,a multi-classification analysis method is proposed,and the minimum distance method and Isodata method are improved.The principle and steps determining the typical fatigue load states by means of the principal component analy- sis and multi-classification analysis are suggested. The calculating program is briefly introduced. Finally,an example using this procedure to the flight measured data of a kind of fighter aircraft is given.

Key words: principal component analysis, cluster analysis, fatigue (materials)