Provided in the present invention are a di-substituted maleic amide linker conjugated to an antibody and a preparation method and use thereof. In particular, the present invention conjugates a strongly cytotoxic active substance to a biomacromolecule through a class of new linkers. The class of linkers can selectively act simultaneously with disulphide chains, so as to greatly improve the substance homogeneity of a conjugate. The conjugate prepared by the linker of the present invention has a high inhibitory activity on a cell strain expressing the corresponding antigen. Also provided is a method for preparing the above-mentioned conjugate and the use.
