Purpose With the increasingly fierce market competitions, non-linear development of organizations through bootlegging has become a key path for enterprises to advance competitiveness. Motivating employees to carry out bootlegging in an organization is becoming an important issue many enterprises face now. This paper aims to analyze the relationship between leader’s positive humor and employee bootlegging. We introduced norm violation acceptability as the mediating variable and trust in leader as the moderating variable to propose a theoretical model and verified it by structural equation modeling (SEM) and multiple regression analysis separately. Patients and Methods Based on both the emotion as social information theory and the social information processing theory, a sample of 278 professional employees working in an information technology (IT) enterprise of China was used to test the moderated mediation model. We used SPSS and AMOS to further verify the research model through structural equation modeling (SEM) and multiple regression analysis. Results The results indicate that there is a positive relationship between leader’s positive humor and employee bootlegging, which is partially mediated by norm violation acceptability. Moreover, trust in leader not only moderated the relationship between leader’s positive humor and norm violation acceptability but also strengthened the influence of leader’s positive humor on employee bootlegging through norm violation acceptability. Conclusion These findings have implications in identifying factors which contribute to employee bootlegging and providing a theoretical foundation for leaders in an organization.