Nano materials prepared by using apoferritin have the advantages of controllable size and single structure, and also have great advantages in catalysis. In this paper, apoferritin/lead selenide (apo/PbSe) composites were prepared by template synthesis and two-step method, with the template of apoferritin, the selenium source of selenium urea, the raw materials of ammonium acetate and lead acetate. The materials were analyzed by transmission electron microscopy (TEM), X-ray diffractometer (XRD), energy dispersive X-ray spectroscopy (EDS), ultraviolet visible spectrophotometer (UV-vis) and fluorescence spectrometer (PL). The catalytic degradation performance of apo/PbSe composites for the wastewater dye methyl orange under visible light was measured. The results show that the main mineral core in the protein is PbSe, and the apo/PbSe composite photocatalyst is successfully synthesized. The best experimental conditions of the composite photocatalyst are pH=3.0, H2O2 mass fraction of 9%, and the degradation efficiency of methyl orange can reach 97.10%. The stability of photocatalytic efficiency is proved by five cycle degradation experiments. Based on the above results, it is shown that apo/PbSe has good catalytic activity and stability, and the photocatalytic degradation mechanism of methyl orange by apo/PbSe composite is proposed.