The present invention relates to a method for activating an absorption layer of a semifinished thin-film solar cell. The absorption layer comprises CdSexTe1-x, CdSe, CdS or CdTe. The method for activating an absorption layer of a semi-finished thin-film solar cell comprises the following steps: providing a semi-finished thin-film solar cell, which has an absorption layer comprising a CdSexTe1-x layer or comprising at least two layers selected from CdS, CdTe, ZnTe and CdSe; forming a polyvinyl chloride film on the surface of the absorption layer; and carrying out a heat treatment on the semi-finished thin-film solar cell having the polyvinyl chloride film on the surface thereof, wherein the temperature of the heat treatment is between 300°C and 500°C.