When flushing the bladder catheter can be divided into intermittent flushing and continuous flushing, intermittent flushing catheter is intermittently open and closed, continuous flushing catheter is open. 1. Intermittent flushing: when flushing the bladder, there should be two lumen catheter, inject about 200ml of sterile saline or other perfusion fluid into the catheter, and then clamp the urinary catheter for about half an hour, open the catheter, and release the flushing fluid, which can complete the flushing of the bladder for once. 2. Continuous bladder flushing: When flushing the bladder, three lumen catheters should be placed, and the three lumen catheters have separate openings for continuous flushing, which can be carried out with saline or other flushing solution for continuous open flushing, and the time of flushing needs to be decided according to the condition. Whether the catheter is open or closed when flushing the bladder should be chosen according to the specific reason, under the guidance of the doctor.