Microwave atomic clocks based on trapped ions have advantages in miniaturization and mobility. Therefore, they have attracted widespread attention. Among them, the 113Cd + ion has become the main candidate ions for the new generation of practical ion microwave clocks due to its advantages of low laser requirements and large ground-state hyperfine splitting frequency. In recent decades, multiple experimental teams at home and abroad have conducted research on cadmium-ion microwave clocks. This article provides a detailed introduction in chronological order of the technical routes and the latest developments adopted by different experimental teams at home and abroad in the research of cadmium-ion microwave clocks.