As a new dam type, Hardfill dam has been arisen recently. The suitable geologic condition of t Hardfill dam construction was analyzed based on considering its characteristics in this paper; it was also studied how to choose the reasonable impervious and drainage system to control the dam body and foundation’s seepage on a given geologic condition to make sure the safety of the project. On the basis of analyzing the foundation geologic conditions of many common dam types, two kinds of typical Hardfill dam foundation were put forward. The seepage field law of dam foundation was analyzed by dam foundation seepage discharge, uplift pressure and seepage gradient of some typical positions after setting reasonable impervious and drainage measures on the two kinds of dam foundations. It is indicated by the calculation results that the adaptability of Hardfill dam foundation is comparatively nice, and the safety of dam foundation can be ensured if appropriate impervious and drainage measures are adopted.