Photoswitchable fluorescent dithienylethene is one kind of the most typical diarylethene structures. Owing to its excellent fatigue resistance and unique thermal bistability

it has been widely studied and applied. This paper reviews the development history of photoswitchable fluorescent thienylethenes

summarized the mechanism of fluorescence photoswitching mechanisms

describes some important achievements on the foundational research about novel structures and improved properties of photoswitchable fluorescent thienylethene in recent years. We also focus on the systemic overview of the applications of photoswitchable fluorescent dithienylethylene in optical memory

non-destructive read-out

single-molecule fluorescence imaging

bio-imaging

all-optical transistors. In the end

the challenges encountered during the study of diarylethenes are analyzed. It is believable that photoswithcable fluorescent polymers based on dithienylethene is the research direction in the future. Moreover

the promising application of diarylethenes in super-resolution imaging is prospected.