Aiming at the needs of permeability test in anti-seepage engineering, this paper discussed the application of flexible wall parameter in testing permeability coefficient of cement-soil concretion body. It is proved that the flexible wall parameter can be used in quality test in anti-seepage engineering with good sealing and fast testing speed and not requiring high to the sample. Unattended digital data acquisition treatment system was adopted with artificial influence reducing and test precision increasing, the working efficiency was improved by quick and convenient operation.