Histone deacetylase (HDAC) is an important target in cancer treatment, and several HDAC inhibitors have been approved for clinical treatment. Compared with single-target drugs, multi-target drugs have better drug efficacy and specificity, can effectively improve the efficacy and reduce the drug resistance, and have great prospects for the treatment of Alzheimer's disease, mycosis, tumor and other diseases. This article mainly introduces the research progress of HDAC dual-target inhibitors in anti-Alzheimer's disease, anti-fungi and anti-tumor fields, so as to provide reference for the development and application of the drugs.