The unethical pro-organizational behavior in corporate low-carbon emission context (low-carbon UPB) and its social interacting mechanism were overlooked by previous studies. The present study addressed this gap by surveying a representative Chinese working population (n = 583). Results showed that employee’s organizational identity is negatively correlated with low-carbon UPB, which is mediated by their concern for the organization’s long-term interests. Additionally, both high-quality leader–member exchange relationships and perceived high inter-organizational competition strengthen this negative relationship. The findings contribute valuable insights for promoting sustainable practices in organizations and reducing unethical behavior in corporate environmental reporting. This study underscores the importance of fostering strong organizational identity and long-term sustainability goals to mitigate unethical pro-organizational behavior in corporate low-carbon UPB and promote ethical behaviors in corporate settings.