The study of terahertz artificial electromagnetic metamaterials is constantly challenged by the problems of large loss, poor performance, and inflexible control. Superconducting materials exhibiting extremely low losses are among the best materials for high-performance functional devices in terahertz band. As such, this paper introduces terahertz superconducting artificial electromagnetic metamaterials, along with a detailed summary of their functionalities of low loss and flexible control. With respect to the application requirement of high performance, an analysis of the development trend, existing problems, and key scientific issues on terahertz functional devices is provided herein.