CLDN6 is a member of the CLDNs family that is specifically and highly expressed in cancers such as ovarian, testicular, endocervical, liver and lung adenocarcinoma, but hardly expressed in adult normal tissues. CLDN6 is able to activate multiple signaling pathways, which take part in the development and progression of cancer, including promoting tumor growth, migration and invasion, and promoting chemoresistance in cancer. In recent years, CLDN6 has received much attention as a novel target for cancer therapeutics. Many types of anticancer drugs targeting CLDN6 have been developed, including antibody-conjugated drugs (ADC), monoclonal antibodies, bispecific antibodies, and chimeric antigen receptor T-cell immunotherapy (CAR-T). This paper briefly summarizes the structure, expression and function of CLDN6 in tumors, and reviews the current status and ideas of developing targeted CLDN6 anticancer drugs.