A T-Hg(Ⅱ）-T structure with base mismatch was formed based on the proton-substitution reaction between mercury ions and thymine,which could be used as a good recognition component for novel mercury ion sensors.Compared with the traditional detection methods,the new mercury ion sensors with T-Hg(Ⅱ）-T mismatch structure as recognizer had some advantages in efficiency and precision.In this paper,research progress and trend of this mercury ion sensors with T-Hg(Ⅱ）-T structure as recognizer based on different types of reporter groups were summarized,thus providing a reference for the development of mercury ion sensors.