Abstract: The interaction between drug molecule and its target is the basis for its pharmacological activity. "Target fishing", as an emerging technology to identify targets, is widely used in the identification of targets of biologically active ingredients, but there is a problem that the active ingredient is hydrolysed by proteases after binding to the target and is thus unstable, so more and more photo-affinity-labelled probes have been developed with the aim of improving its binding stability. This paper reviewed the types and applications of photoaffinity groups in photoaffinity labelled probes in recent years.