An antibody-drug conjugate (ADC) has a structure represented by Formula (I): a pharmaceutically acceptable salt thereof wherein Ab is an antibody without glycans (i.e., the protein portion an antibody)； G1 and G2 are glycan moieties, which may be the same or different； Cn1 and Cn2 are conjugation moieties, which may be the same or different； L1 and L2 are linker moieties, which may be the same or different； D1 and D2； are drug units which may be the same or different； and x and y are independently an integer from 0 to 8, provided that x+y≠；0.
