Abstract: Aiming at the disadvantages of oil - base cernent slurry in application, this paper introduced the composition and performance of oil - base cement slurry. The oil cabase cement slurry does not solidify when it encounters oil but it will solidify quickly when it encounters water. These characteristics made oil-base cement slurry have a wide application prospect in oil-stabilization and water-control, oil reservoir protection, EoR and so on.This paper also sorted out and analyzed the water-plugging application of polymer and oilbase extra fine cement slurry in HAYS area, KANSAS of America.