In the paper, we report on the visible photocatalytic activity and antiphotocorrosion performance of CdS quantum dots (CdSQDs) by the combination of polyaniline with the modification of the carboxyl group, which was prepared by an N-substituted carboxyl group polyaniline (NPAN) cadmium precursor. The photocurrent response and photodegradation of Rhodamine B experiments show a higher current output and photocatalytic activity for the CdSQDs/NPAN hybrid photocatalysts in comparison with the mechanical blends of CdS nanoparticles and NPAN, as well as pure CdS nanoparticles. The enhanced photocatalytic performance could be attributed to the hybrid effect between CdSQDs and the carboxyl group in the polyaniline matrix. TEM morphology and XRD patterns of CdSQDs/NPAN hybrids had no significant differences before and after the photocatalytic oxidation, indicating that the incorporation of the carboxyl group in polyaniline could completely inhibit the photocorrosion of the CdS semiconductor. A possible photocatalytic mechanism of the CdSQDs/NPAN hybrid photocatalysts was proposed in accordance with the experimental results.