The invention discloses a folded cannula used for dacryocystorhinostomy and a preparation method thereof. The folded cannula includes a drainage header pipe and a drainage branch pipe, and a bubble bag is arranged on the drainage header pipe; an oval drainage disc and a tail fixing screw are arranged at both ends of the drainage branch pipe respectively, the tail fixing screw extends to an internal hole forming part of a nasal cavity, and a cannula body used for fixation is installed on the tail fixing screw through a buckle. A hollow silica gel catheter is selected, after the two ends of thesilica gel catheter are penetrated, the silica gel catheter is adopted as the drainage header pipe, and the drainage branch pipe is fixedly installed along the central axes of the two ends of the drainage header pipe; the end faces of the outer side of the drainage branch pipe are all polished, and the oval drainage disc and the tail fixing screw are additionally arranged; according to shape requirements, heating for shaping is conducted on the drainage pipes. More convenience is provided for implanting, extra traction devices are not required, complicated treatment such as knotting is not required in the nasal cavity, patients feel comfortable, and no secondary injuries are caused; by designing the drainage pipes in hollow shapes, tears can be drained normally, infection is not caused easily, and symptoms are alleviated obviously during implanting.