Research conclusions: After making the comparative analysis of various programs for pile foundation pit，the cofferdam bracing way with steel sheet pile in the single layer was adopted and with it the supporting structure facilitated the easy construction and mechanical excavation of borrow pit with feature that the construction could be conducted easily and rapidly to ensure the levee safety during construction period and the levee recoverability after construction． The concrete would be poured to the pile cap as a whole for one time． According to the simulation analysis result of the temperature field of hydration heat during the mass concrete construction period of the pile cap，the temperature reducing system with buried cooling water pipelines and the temperature monitoring system with electronic components were used to guarantee the concrete construction quality of the pile cap．