The invention discloses a preparation method of core-shell polyphenol surface finish collagen polypeptide nanospheres. The preparation method comprises the following steps: taking and dispersing collagen polypeptide nanospheres in distilled water, regulating the pH of a system to be 4-7 while stirring, then adding a polyphenol substance, stirring for reaction, centrifuging and separating to obtain solid microspheres; taking and dispersing the solid microspheres in distilled water, stirring, and adding a penetrant and a cross-linking agent, stirring for reaction, adding a fixing agent, adjusting the pH to 5-8, standing, centrifuging, and separating to obtain a solid, and drying the solid in vacuum to obtain the core-shell polyphenol surface finish collagen polypeptide nanospheres. According to a tanning chemical principle, the surfaces of the collagen polypeptide nanospheres are coated with the layer of the polyphenol substance to enhance the content of active functional groups, and particularly the adsorption processing capacity of a polyhydroxy structure having higher complexing power for heavy metal ions is enhanced, and a production process is simple, high in operability and easy to generalize, and an obtained product has higher promotional value and has a well application prospect.