There is a lack of cost analysis of super largediameter subsea shield tunnel in China. Hence, the cost of Maliuzhou Shield Tunnel in Hengqin, Zhuhai, China is analyzed and studied to provide theoretical support for cost management of relevant enterprises. The influences of sea conditions, i.e. beadrock heave, seawater corrosion, complex formation, tide, wind, etc., on shield tunnel cost are studied by measuring the consumption of labors, materials and equipments; and then the consumption of labors, materials and equipments during shield assembly and disassembly, shield tunneling, synchronous grouting and segment assembly is analyzed; and a suit of enterprise quota for super largediameter subsea shield tunnel is obtained. The results can provide reliable support for fine management of budgetary estimate and settle accounts of enterprises, provide reference for our nation to publish shield tunnel quota and improve productive efficiency, and promote the development of social productivity.