With the broad application of modern diaphragm wall engineering,problems including inaccurate depth of buried pipes control during pouring of underwater concrete and large-area exposure of the reinforced bar for the diaphragm wall after excavation of the foundation pit exposed gradually.For the purposes of strengthening the project process control and improving the quality of diaphragm wall,we put forward the concept of the membrane effect of underwater pouring concrete and its formation stages and nature for the first time taking the underwater pouring concrete as the investigation objective.At the same time we put forward the concept of taking the membrane thickness as the measurement standard and the membrane resistance as the characterization method.According to field tests and theoretical analyses,we get to know the influential factors of the membrane effect,and put forward main measures for controlling the depth of buried pipes.According to the characteristics of the membrane effect and large-area exposure of the reinforcement,we put forward the concept of edge-membrane stranding effect and the influential factors for the first time.Based on the cause analysis of large-area reinforcement exposure,we put forward main measures for reducing the large-area reinforcement exposure.