<p>The pollution generated during highway construction has become increasingly severe. Existing studies indicate that surface pollution not only intensifies environmental pressure but also significantly compromises pavement quality and service life. To reduce pavement pollution and promote green road construction and sustainable development management, this study focuses on the construction phase of highway development. For the first time, a pavement pollution assessment indicator System is established from the perspective of pollution sources, covering four dimensions: construction material pollution, construction operation pollution, construction machinery pollution, and construction environment pollution. An integrated method combining an improved Analytic Hierarchy Process–Entropy Weight Method (AHP–EWM) with the grey clustering method is employed to comprehensively assess pollution on the pavement and its surrounding environment during the construction phase. The study applies the newly developed pollution assessment system to an actual highway construction project. The results indicate that the overall pollution level of the project is classified as “mild pollution.” Among the assessed categories, Cross-Construction Pollution is identified as “severe pollution,” while Oil Pollution and Soil and Rock Pollution are classified as “moderate pollution.” These findings demonstrate the rationality and wide applicability of the proposed assessment system and evaluation model. Finally, this study proposes effective prevention and control measures targeting the various pollution sources contributing to pavement pollution. It fills a research gap in the field of highway construction pollution and provides important guidance for pollution mitigation and green construction management during pavement construction.</p>