The invention discloses a surface nanofilm processing method prior to plastic packaging in semiconductor packaging. The surface nanofilm processing method is characterized in that the surface nanofilm processing method includes the following steps: step a: a small amount of adhesion promoter solution is uniformly applied on the surface of a material to be processed and attached on the surface to be reinforced; step b: the solvent in the adhesion promoter solution is volatilized and air-dried under the normal temperature or dried by way of baking, the thickness of an adhesion promoter active ingredient coating after volatilization is controlled at nanometer-grade thickness, and the adhesion promoter active ingredient coating and the surface to be reinforced on the material to be processed are chemically bonded; step c: the subsequent plastic packaging process is carried out, and the functional group of the other side of the nanometer-grade thickness adhesion promoter active ingredient coating already chemically bonded with the surface of the material to be processed is chemically bonded with epoxy resin used in the plastic packaging process. The surface nanofilm processing method can enhance the bonding strength of a plurality of key interfaces in chip packaging to a certain degree, prevent layering and cracking in the technological process and decrease the moisture level.