Abstract: Antibody-drug conjugates (ADCs) are new type of drugs that connect antibody and small molecule payload through a linker, and use antibody as carrier to target and transport payload to specific cells. With the launch of the first domestically developed ADC, Disitamab vedotin, ADCs are becoming more widely used in the clinical practice. ClinicalTrial.gov shows 1,685 ongoing clinical trials by February 2022. A total of 14 ADCs have been approved in the worldwide, of which 12 drugs have been approved by FDA, 1 by NMPA and 1 by PMPA. After decades of development, the technology for ADCs has been broken through. The design of key ADCs structural elements, such as the antibody, payload, linker, and conjugate technologies, has been developed rapidly in recent years. At the same time, the application of ADCs brings many problems and challenges. To better understand the nature of ADCs, we review the progress of the aforementioned technologies.