Seepage control techniques for earth-rockfill dams built on a thick overburden layer are reviewed from the perspectives of the vertical cutoff technique, horizontal anti-seepage technique, and joint seepage control. Innovations and breakthroughs in the seepage control of earth-rockfill dams on a deep alluvion foundation using the concrete anti-seepage wall, the grout curtain, a wall and curtain combination, and horizontal coverage techniques are described. And the applications of the FEM and BEM methods in numerical simulation of seepage control for earth dams are introduced. As applied to three typical engineering projects, reasonable seepage control measures and their optimization for earth-rockfill dams on a thick overburden layer were studied. Some suggestions and key issues for seepage control of earth-rockfill dams on a thick overburden layer are described.