In order to improve the evaluation efficiency of commercial aircraft maintenance ability, a PCA method is proposed to evaluate it. The principle of principal component analysis is introduced and the factors that affect the maintenance capability of commercial aircraft are summarized. The evaluation index system of commercial aircraft maintenance support system was established, and the different maintenance support schemes were evaluated by SPSS software to ensure the integrity of airworthiness of the aircraft. The results show that this method eliminates the influence of subjective factors on the evaluation. The obtained evaluation indexes can be used for the quantitative evaluation of the maintenance ability of commercial aircraft. The evaluation results can provide references for airlines and maintenance organizations.