The invention discloses a mixed film with crosslinked quantum dots and carrier, a preparation method and a QLED device. The method comprises the following steps: mixing the quantum dots and the carrier in a solvent to obtain a mixed liquid; preparing the mixed solution into a mixed film containing the quantum dots and carrier by a solution method; putting the mixed film containing the quantum dotsand the carrier into an HHIC reactor, introducing H2 and unsaturated gas into the HHIC reactor, so that cross-linking occurs between the quantum dots and the carrier, and the mixed film with crosslinked quantum dots and carrier is obtained. The invention utilizes HHIC technology to cross-link the quantum dots and the carrier in the mixed film to obtain the mixed film with the crosslinked quantumdots and carrier. By utilization of the HHIC technology, the quantum dots and the carrier of the invention are connected together through a carbon chain, thereby facilitating transfer of charges through the carbon chain and improving the charge transfer capability. At the same time, unsaturated gas is introduced which contains unsaturated bonds. After crosslinking, indefinite pi bonds are formed,which can conduct electricity and improve the photoelectric properties of the film.