The sustainable development of infrastructure construction projects heavily depends on favorable cooperation of all parties and ethical code of conduct, while Un-ethical pro-organizational behavior (UPB) may undermine the mutual efforts and cause serious consequences. UPB has aroused wide interest of researchers, but what may trigger construction employees to engage in UPB at team-level has not been elucidated completely. With information asymmetry and huge uncertainty, the behaviors of employees in temporary project teams are marked by environmental and personal characters. The study discusses the influences of collective moral judgement focus on self (CMJS) and Machiavellianism on UPB. Through a moderated mediation analysis conducted on a set of survey data from Chinese construction projects, the empirical results of the two-level hierarchical linear model indicate that CMJS positively impacts UPB directly, and meanwhile Machiavellianism acts as a partial mediator in the relationship between CMJS and UPB. The findings also reveal that performance-avoidance goal orientation (PAGO) and motivation to learn (MTL) moderate and strengthen the relationship between Machiavellianism and UPB. The study offers practical suggestions for both project managers and policymakers of construction projects.