With the institutionalization and normalization of volume-based procurement, each region has carried out trans-regional alliance with volume-based procurement, and actively explored and improved drug purchase mechanism. By combining the purchasing quantity of municipal public medical institutions and trans-regional public medical institutions, the drug group purchasing organization in Shenzhen carried out the drug group procurement on behalf of the medical institutions with the mode of "comprehensive evaluation plus group negotiation plus expert review system". This paper analyzes the influence and function of the expert review system through the practice and achievements of the expert review system in drug procurement in Shenzhen, and provides suggestions for improving the drug procurement mechanism.