Abstract: This is an essay in the field of ceramics and composites. Alkali-activated geopolymer is a new kind of inorganic cementitious material, which is formed by cross-linking of silicon-oxygen tetrahedrons and aluminum-oxygen tetrahedrons through the bridging oxygen atoms. The negative charges of aluminum-oxygen tetrahedrons are balanced by alkali metal cations. Due to its three-dimensional network structure, geopolymers have excellent properties such as high mechanical properties, good durability, and excellent heat resistance. They have been widely used in the high-performance construction materials preparation, wastewater treatment, and solid waste recycling. This article reviews the research progress of the reaction mechanism, microstructure, and mechanical properties of alkali-activated geopolymers. In addition, the development of its application research in the fields of building materials, environmental pollution control, and solid waste resource utilization is also introduced in this article in order to comprehensively understand the research status of alkali-activated geopolymers.