The defect formation energy of each system after P doped ZnO was predicted using the BP neural network optimized by the Adam algorithm, the analysis shows that the most easily formed systems are the ZnO∶PZn and ZnO∶PZn (2VZn) systems, otherwise the ZnO∶PO and ZnO∶PZn (1VZn) system, and the photoelectric characteristics of each system on the basis of first principles were studied. The analysis shows that the ZnO∶PZn system is n-type conductive, with a band gap of 0.78 eV, which is larger than the intrinsic system. ZnO∶PZn (2VZn) system is p-type conductive, and the band gap is similar to the intrinsic system. The electrical conductivity is similar to the ZnO∶PZn system, which is much higher than the ZnO∶PZn (1VZn) system, and the reflectivity, absorptivity, light transmittance are better than intrinsic ZnO system.