Adenosine activated protein kinase (AMPK) is a serine/threonine protein kinase that can sense the change of intracellular energy. AMPK plays a critical part in the occurrence and development of tumors. According to the difference of AMPK catalytic subunits, it is divided into AMPKα1 and AMPKα2. The AMPKα1 subunit is the catalytic subunit of AMPK and is extensively distributed in the various tissues and organs. This review focuses on the structural, activated and functional aspects of AMPKα1 and the involvement of AMPKα1 in the regulation of intracellular substance metabolism, and summarizes the respective performances of AMPKα1 in different cancers and the corresponding potential applications of AMPKα1 as a drug target in the relevant cancers. AMPKα1 can be used as a diagnostic marker or drug target for cancer diagnosis and therapy, providing an idea for cancer treatment, which has importance clinical significance.