Abstract: Under the background of green and low-carbon development, energy, transportation, water conservancy and other infrastructure projects are being accelerated to build the construction of a high-quality living circle suitable for residence, industry and tourism in megacities. As a result, substantial amounts of sand and gravel are being produced during engineering construction, and their resource utilization has attracted significant attention. Given the lack of front-end evaluation for sand and gravel resource utilization during engineering construction in megacities, this study analyzes relevant disposal rules and policies issued by Shenzhen over the past two years. Furthermore, taking a water conveyance project in Shenzhen as an example, this study puts forward a resource evaluation and comprehensive utilization model based on the coupling of four key factors: surrounding rock classification, construction methodology, adverse geological conditions and stratum lithology. Application of this model estimates the recycled sand and gravel volume at approximately 1.6524 million m³ in the water conveyance project, yielding a comprehensive utilization benefit value of approximately 29.6579 million yuan. The evaluation was conducted using this model to further verify its feasibility and rationality, which can promote the deepening development of sand and gravel resource utilization in engineering construction. At the same time, through reasonable resource evaluation and comprehensive utilization, the sand and gravel resources generated by engineering construction can be classified and defined, and converted into valuable resources according to market behavior, bringing additional economic benefits to engineering construction and government finance, alleviating resource shortage pressure, and reducing engineering costs. The results indicate that this model can promote the front-end evaluation of sand and gravel resource utilization and the graded utilization of back-end （building stone＞mechanism sand parent rock＞backfill material）, providing technical support and engineering practice reference for the practice of green and low-carbon construction in mega cities. Finally, it is proposed to strengthen the management of sand and gravel resources from the perspective of engineering construction planning and site selection research, promote the front-end evaluation of sand and gravel resources during the development and reform project initiation stage, and enhance the comprehensive utilization capacity of sand and gravel resources; At the same time, it is suggested to improve the cross regional resource allocation mechanism, reduce the risks of external transportation and storage, and support the green and low-carbon development goals of mega cities.