The sea area project of the supporting terminal project of the second phase of Suizhong Power Plant is located in the uncovered waters of the Bohai Bay offshore.It is affected by winds and waves all year round,and the winter temperature is low and the durability requirement of concrete is extremely high.The concrete T-beam of the approach bridge is a post-tensioned pre-stressed structure.According to the comprehensive performance requirements,we select high-quality raw materials of concrete,analyze the microstructure of concrete by scanning electron microscopy,compare the influence of different admixtures and admixtures on the performance of hardened concrete,and apply the absolute volume method to design mixing proportion of pre-stressed and high performance anti-freezing concrete.Through the engineering verification,we finally obtain the mixing proportion of the concrete which meets the construction and design requirements.