Hydrogels, with high water content, have soft texture and excellent biocompatibility. Among them, intelligent hydrogels have attracted much attention due to their excellent environmental responsiveness. The intelligent hydrogels emerge in endlessly in recent years, the mechanical strength of intelligent hydrogels changes from tens of Pa to tens of MPa, and they can be applied in biomedicine including drug carriers, tissue engineering scaffolds, etc. Based on this, this paper summarizes the development and applications of intelligent hydrogels in recent years. Firstly, hydrogels can be classified into different types according to different classification methods. Furthermore, this paper mainly summarizes different types of intelligent hydrogels, including temperature sensitive hydrogels, pH responsive hydrogels and self-healing hydrogels, also elaborates and analyzes the experimental cases of each kind of intelligent hydrogels in detail. Finally, the applications of various intelligent hydrogels in biological fields are summarized, including drug delivery, cell loading and delivery, wound dressing, etc.