A polymer solar cell includes a photoactive layer, a cathode electrode, and an anode electrode. The photoactive layer includes a polymer layer and a carbon nanotube layer. The polymer layer includes a first polymer surface and a second polymer surface opposite to the first polymer surface. A portion of the carbon nanotube layer is embedded in the polymer layer, and another portion of the carbon nanotube layer is exposed from the polymer layer. The cathode electrode is located a surface of the carbon nanotube layer away from the polymer layer. The anode electrode is located on the first polymer surface and spaced apart from the carbon nanotube layer. The entire second polymer surface is exposed.