Photodynamic therapy endoscope is a key device for intracavitary photodynamic therapy by combining medical endoscopic system with photodynamic therapy technology, which can transmit the therapeutic laser beam to the target tumor location through the biopsy channel to realize intraoperative real-time monitoring and treatment, and improve the precision and safety of photodynamic therapy. This paper elaborates and analyzes the research progress of the principle of photodynamic therapy and medical endoscopes from the three directions of visualization photodynamic therapy endoscopes, coaxial photodynamic therapy endoscopes and photodynamic diagnostic and therapeutic endoscopes, and looks forward to the research prospect of photodynamic therapy endoscopes.