As an industrial byproduct of smelter operations, smelting slag has brought certain environmental issues including without taking safety precautions or using appropriate management. Through a thorough analysis of the literature published in the last years, the latest research progress on the characteristics, resource utilization pathways, and safety utilization evaluation of non-ferrous metal smelting slag was introduced in this work. Key findings indicate that different ore concentrate materials, smelting conditions and types determine chemical and mineralogical characteristics of smelting slag. Moreover, smelting slag exhibits extremely high flexibility in various applications, not only as metal recovery and construction materials, but also as agricultural fertilizers and remediation agents. At the same time, the importance of conducting strict safety assessments under various utilization scenarios to mitigate its potential environmental risks is emphasized. In addition, this article also emphasizes the direction of future research, including creating a comprehensive and quantized environmental risk assessment method of heavy metals in soil-slag mixtures, as well as exploring more innovative utilization methods of smelting slag. Overall, this review is significant for promoting research on the use of smelting slag in environmental protection and sustainable resource utilization.