The present disclosure provides a gene editing nanocapsule and a preparation method and use thereof. The gene editing nanocapsule has a core-shell structure, wherein the inner core includes a Cas/sgRNA ribonucleoprotein complex, and the outer shell includes a polymer, the Cas/sgRNA ribonucleoprotein complex has a gene editing function, and the polymer acts as a carrier for the Cas/sgRNA ribonucleoprotein complex and protects it, because the polymer contains tumor microenvironment sensitive molecules, the nanocapsules can be efficiently released in tumor cells. Further, the surface of the outer shell can be modified with a targeting agent, so that the nanocapsule can specifically target tumor cells, which improves the endocytosis efficiency of the nanocapsule. The gene editing nanocapsule has good biocompatibility and biosafety, and is expected to become a safe and efficient gene therapy drug for tumors.