High-temperature melts, including molten metals and molten melts, are common substances in the pyrometallurgical process. Temperature is one of the most concerned and important physical properties of melts. Maintaining a melt’s molten state means huge energy consumption. Moreover, the temporary storage, transfer, and subsequent processing of them are usually accompanied by considerable risks. Thus, real-time temperature measurement of the melt is one of the core requirements. Due to the high corrosiveness of molten phases, invasive temperature measurement is no longer applicable or even could not deploy in high-temperature melts. Therefore, optical temperature measurement technology has been brought into prime focus. This paper provides a review of the academic improvement involved and commercial technology employed in each optical temperature measurement device. Recent progress and trends are investigated in both radiation thermometers and computer vision-based pyrometers. The measurement principle and characteristics of each device are discussed in detail. The optimization of accuracy is emphasized based on radiation thermometers, while the reasons for a few computer vision-based pyrometers are mentioned. In addition, a new temperature diagnosis technology that combines computer vision and artificial intelligence has received widespread attention and applications in recent years. Future developments are briefly introduced to provide some insight into which direction the development and application of temperature measurement technologies are likely to develop.

高温熔体，包括熔融金属和熔融熔体，是火法冶金过程中的常见物质。温度是熔体最受关注和最重要的物理性质之一。保持熔体的熔融状态意味着巨大的能源消耗。此外，它们的临时存储、转移和后续处理通常伴随着相当大的风险。因此，熔体的实时温度测量是核心要求之一。由于熔相的高腐蚀性，侵入式温度测量不再适用，甚至无法部署在高温熔体中。因此，光学测温技术已成为人们关注的焦点。本文回顾了每种光学温度测量设备所涉及的学术改进和商业技术。研究了辐射温度计和基于计算机视觉的高温计的最新进展和趋势。详细讨论了每种设备的测量原理和特点。基于辐射温度计强调精度的优化，同时提到了一些基于计算机视觉的高温计的原因。此外，一种结合计算机视觉和人工智能的新型体温诊断技术近年来受到广泛关注和应用。