The paper studied the effect on the performance of organic polymer solar cells at the active layer based on P3HT/PCBM from the addition of a solid derivative of nitrobenzene, 1-Bromo-4-Nitrobenzene, carried out experiment on 1-Bromo-4-Nitrobenzene doped with different doses in P3HT/PCBM active layer, and comparatively analyzed the performance parameters, absorption intensity, external quantum efficiency, fluorescence intensity, morphology characterization, and transient absorption of devices under different doses. Results showed that the organic polymer solar cells reached the maximum energy conversion efficiency, the energy conversion efficiency was improved from 2.2% to 3.4%, with an increase of 54 %, when the additive volume of 1-Bromo-4-Nitrobenzene was 25wt%. Addition of 1-Bromo-4-Nitrobenzene helped to improve the photoelectric conversion efficiency of organic polymer solar cells.