Steel slag, the main solid waste in the steel-making process, is produced more than 120 million tons annually in China. Most of the steel slag was stored in the open air, which brought potential safety and environmental protection risks such as land occupation and infiltration of heavy metal components into the soil. In recent years, the utilization and application of steel slag have garnered considerable interest and expanded significantly in various industries. This paper summarized the comprehensive utilization status of steel slag in building materials, agriculture, wastewater treatment, marine engineering, ceramics, and CO₂ mineral carbonation and sequestration in recent years domestically and internationally and analyzed why steel slag's application was limited in various fields. On this basis, steel slag and slag composite micro powder (SSCM) technology was proposed, which realized the high added value and utilization rate of steel slag in industrial applications. This review provided guidance for selecting and developing secondary resources of other solid wastes containing metallurgical slag.