With the increase in air travel, comfort is becoming an important issue with which airlines differentiate themselves in a competitive market. Passengers are paying more attention to their comfort experience during flights. However, passenger comfort is affected by various factors that result from the complex cabin system. Besides, the factors have interrelations between one another. How to identify the key factors and comb through their interrelations to improve passenger comfort efficiently is a critical problem in cabin design. To solve this problem, a hybrid model is proposed to identify the key factors and discuss the interrelation between them based on the questionnaire data. First, factor analysis is conducted to segment complex influencing factors into groups and to extract the most important factors. Decision Making Trial and Evaluation Laboratory (DEMATEL) method and fuzzy set theory are combined in the next analysis, considering both the interrelation between factors and the fuzziness of subjective comfort perception concurrently. It forms a structural model and then visualizes the causal relationships among factors through a causal diagram. The results of an empirical study show that the proposed model is capable of identifying the critical factors that affect passenger comfort effectively and could offer a priority of factors to improve passenger comfort.