Ultrathin flexible concrete seepage-proof wall construction method has many advantages in various underground seepage control projects. This technology was applied in the seepage control project of Pudong Liming landfill site reconstruction, which was the first case of the similar project in China. Based on this project case, discussion was made on the application of ultrathin flexible concrete seepage-proof wall construction method about construction technology and quality control, and some suggestions were also made on reasonable selection of seepage control technology.