Abstract: This paper introduces the basic functions of acrylic acid emulsion mortar. After comparing with other kinds of materials used to rapair concrete,the plan is made out to repair the spillway surface in Panjiakou dam. The Paper explains the repairing experience,incluing modifying the ratio,improving technology and management,and the good results have been achieved. Thin layer repairing also gets good results in the places where freezing,scouring and rubbing are forbidden.