This study, based on self-determination theory and psychological capital theory, aims to explore the relationship between job autonomy, psychological capital, and job crafting behavior among white-collar employees in Chinese enterprises during the VUCA era. Additionally, it examines the mediating role of psychological capital in this context. A questionnaire survey was conducted among 518 Chinese white-collar employees, covering variables related to job autonomy, psychological capital, and job crafting behavior. Hypotheses were formulated based on self-determination theory and psychological capital theory, and statistical analysis was employed to validate the relationships between these hypotheses. The study revealed a positive relationship between job autonomy and job crafting behavior. Job autonomy exhibited a positive influence on psychological capital. Psychological capital also had a positive impact on job crafting behavior. Furthermore, psychological capital is a mediator between job autonomy and job crafting behavior. Based on their research findings, providing recommendations to enhance employees' autonomy in their work contributes to the strengthening of their psychological capital, thereby fostering a greater display of work redesign behaviors. Therefore, organizational managers should prioritize and create a work environment conducive to the development of employee autonomy, aiming to elevate their levels of psychological capital. This, in turn, enables employees to better adapt to and cope with the challenges of the VUCA era.