With the intensification of the global labor market competition and the individuality of the employees in the contemporary organization, idiosyncratic deals（i-deals） has gradually attracted the attention of the western scholars. As a non-standardized work arrangement with attractive and incentive nature, i-deals can cater to the needs, preferences and expectations of employees, also it provides a practical way to retain the core talent. Empirical studies have showed that i-deals can not only improve i-dealers’ positive affect like organizational commitment and career satisfaction, but also elicit their extra-role behaviors (e.g., voice behavior and helping behavior). However, the existing research relatively ignored the negative impact of i-deals on third-party employees. In order to bridge this gap, this paper explored the influence of coworkers' i-deals on employees' work withdrawal behavior and its associated underlying mechanisms from the perspective of fairness theory. Sample of our study were collected from part-time graduate students of a university located in Guangzhou. To avoid the common method bias, we took three time points to collect data. At Time 1, participants were asked to report their demographic information, perceived the coworkers’ i-deal, and social exchange. Then we continue to ask those participants to evaluate their own psychological contract violation and work withdrawal behavior in Time 2 (two weeks later) and Time 3( four weeks later).We finally got 201 valid questionnaires. Through a series of regression analysis and bootstrapping method, we got three conclusions: (1) Coworkers' i-deals was positively related to employees' work withdrawal behavior; (2) Such relationship was partially mediated by employee psychological contract violation (3) The degree of social exchange between employee and organization moderated the relationship between coworkers' i-deals and employees’ psychological contract violation, such that this relationship was weaken when social exchange was low. The results of this study provide several important theoretical and practical implications. First of all, by exploring the impact of coworkers' i-deals on employees' work withdrawal behavior, this study extend the research on the negative effect of i-deals on the third-party employees, and deepens our understanding of the influence of i-deals. Secondly, by examining the mediating role of psychological contract violation, this study promotes the understanding of the potential mechanism of coworkers' i-deals to predict the effect of employees' work withdrawal behavior. Thirdly, we further examine the moderating effect of the relationship between employees and organizational social exchange, revealing the unique boundary conditions of the differences in the psychological contracts. Beyond the theoretical implications highlighted above, there are also some practical strategies that organizations can use to minimize negative feedback from those who haven't. On the one hand, organizations should pay attention to the development of social relations between employees and organizations, so that employees are more loyal, and trusty. On the other hand, i-dealers should appropriately increase their citizenship behavior in order to restore the sense of imbalance of "pay-return" of third party employees. Finally, the limitations of this study and the direction of future research are discussed.