Prepare nano-ZnO by hydrothermal method, doped into starch substrate by melt blending method, obtain nano-ZnO starch composite material, study the composition of composite material, microscopic morphology, molecular structure, photoelectric characteristics and corresponding law of action, and initially explore composite materials Inhibit the effect of E. coli. The results show that the nano-ZnO powder has uniform morphology, high crystallinity, and an average particle size of about 85nm. KH560 grafted modified nano-ZnO with a grafting rate of 5.26% to 5.86%. The modified nano-ZnO is further bonded to the starch substrate, and the composite material basically maintains the crystal structure. The modification of the nano-ZnO by KH560 improves the dispersion and stability of the doped material in the starch substrate. With the increase of the content of nano-ZnO, the photoluminescence intensity, ultraviolet shielding performance and ability of inhibiting Escherichia coli of the composite material increase, but the light transmittance shows a downward trend. When the nano-ZnO doping amount is 10%, the antibacterial rate of the composite material to E. coli is about 95%.