Single-walled carbon nanotubes have characteristics of good conductivity, baryon transmission performance, and high photoelectric conversion performance of quantum dot composite material. In situ condensation method was used to prepare polymer/poly(2-methoxy, 5-octoxy)-1, 4-phenylenevinylene-single walled carbon nanotubes-PbSe quantum dot composites. X-ray diffraction, transmission electron microscope, UV-vis absorption spectroscopy were applied to study their characteristics. The results indicate: poly(2-methoxy, 5-octoxy)-1, 4-phenylenevinylene, single walled carbon nanotubes and PbSe quantum dots can be effectively combined, especially the single walled carbon nanotubes and poly(2-methoxy, 5-octoxy)-1, 4-phenylenevinylene form a network structure in poly(2-methoxy, 5-octoxy)-1, 4-phenylenevinylene matrix; PbSe quantum dots, each with an average size of 5.75 nm, can be dispersed to form a coating or mosaic structure in the polymer substrate of poly(2-methoxy, 5-octoxy)-1, 4-phenylenevinylene -single walled carbon nanotubes, producing the light induced charge transfer phenomenon. The study of composite photoelectric performance shows that inserting different thicknesses of modification cathode material LiF, improving the photoelectric performance of the composite, and when the thickness of LiF is 3 nm, open circuit voltage is 0.558 V, short circuit current is 2.338 mA, fill factor is 37.6%, conversion efficiency is 0.466%. Compared with that without LiF, the optoelectronic properties increased 30%.