Drainage tube capable of being retrograde placed into renal pelvis through urethra

The utility model discloses a drainage tube reversely placed into a renal pelvis through the urethra. The drainage tube comprises a drainage tube body, a water bag body, a collecting bag and shorts used for fixing the collecting bag. The water bag is arranged on the drainage tube, and the collecting bag is placed on the shorts; a curled drainage head is arranged at one end of the drainage tube, an inner cavity channel of the drainage tube is a drainage channel, the two ends of the drainage channel are open, an inner cavity channel of the curled drainage head is communicated with the drainage channel of the drainage tube, one end of the inner cavity channel of the curled drainage head is open, the other end of the inner cavity channel of the curled drainage head is closed, and a plurality of drainage holes are formed in the curled drainage head. A water injection joint is arranged at the other end of the drainage tube; a water injection channel is arranged on the tube wall of the drainage tube; and a plurality