The invention discloses a ZnO/Ag2O photocatalysis composite material, as well as a preparation method and application thereof. The ZnO/Ag2O photocatalysis composite material, as well as the preparation method and the application thereof have the following technical effects that 1, the ZnO/Ag2O photocatalysis composite material is prepared by one step by adopting a solid phase grinding method, andthe preparation method has the remarkable advantages of simplicity in operation, low energy consumption, high efficiency, high yield, green and environmental protection, and recyclability of substratesodium nitrate, and is suitable for mass production; 2, a p-n node formed between zinc oxide and silver oxide is beneficial to interface electron transfer, the recombination of a photo-induced electron hole pair is reduced, and the catalytic performance is remarkably improved compared with a single semiconductor catalyst; on the other hand, the silver oxide is provided with narrower band gaps compared with the silver oxide, so that silver oxide nanoparticles can be used as an effective photosensitizer under the irradiation of sunlight, so that the visible light catalysis performance of the zinc oxide is improved; 3, the ZnO/Ag2O photocatalysis composite material can be used for degrading organic dye wastewater containing methylene blue, methyl orange and rhodamine B, and can be used for degrading 80 percent or more of target degradation products within 20 minutes at the soonest, so that the degradation rate can be improved by 13 times compared with single zinc oxide, and the excellentphotocatalytic activity is realized.