Abstract Based on the theory of social exchange and ego-depletion, this study explores the relationship between work passion and unethical pro-organizational behavior. Through a two-stage survey of 262 employees, it was found that: no matter whether it is obsessive work passion or harmonious work passion, it is possible to activate employees' unethical pro-organization behavior; self-depletion has partial mediation effect on the relation of obsessive work passion and unethical pro-organizational behavior; organizational identification plays a full intermediary role in the relation of harmonious work passion and unethical pro-organizational behavior; the principle ethical climate not only negatively regulates the relationship between organizational identity, self-depletion and unethical pro-organizational behavior, it also has a mediating effect on organizational identity and self-depletion. The findings of this study help to understand the intermediaries and boundary conditions that affect the unethical pro-organizational behavior, and guide managers to take reasonable measures to effectively manage unethical pro-organizational behaviors in organizational practice and actively guide the work passion of employees.