Environmental labeling certification, as a voluntary environmental regulation tool, represents an important initiative by the government to establish a multi-stakeholder environmental governance system. This paper explores the mechanisms through which environmental labeling certification affects the duration of firm export activities. Using the matched data from the Chinese Industrial Enterprises Database (2000–2014), Chinese Customs, and eco-label certified firms released by the Ministry of Ecology and Environment, this paper treats environmental labeling certification as a quasi-natural experiment and applies a DID model to identify its net effect on export duration. The results show that environmental labeling certification significantly extends export duration. The findings are robust across placebo tests, alternative sample specifications, and adjustments for potential policy interference. The impact of environmental labeling certification on export duration varies significantly depending on corporate financial constraints, industry pollution intensity, and regional levels of digital economy development. Mechanism testing reveals that while environmental labeling certification can increase compliance costs and reduce export duration, it also mitigates information asymmetry and stimulates technological innovation, leading to longer export duration. Further expansion analysis suggests that export resilience improvement positively moderates the impact of environmental labeling certification on export duration. Therefore, expanding the coverage of environmental labeling certification and improving its institutional design are effective means to enhance export duration, stabilize trade relations, and promote high-quality economic development.