A stenosis dilatation catheter is provided, including a catheter, a stenosis dilator is movably provided in the urine passage of the catheter, the stenosis dilation guide includes a tubular stenosis dilation guide body, at that front end of the narrow expansion guide body, the rear end of the guide portion is provided with an air bag, a through hole is arranged on the side wall of the narrow expansion guide inside the air bag, the posterior end of the stenosis dilation guide body is provided with an elastic bag body, the elastic bag body and the stenosis dilation guide body form a sealed spacefilled with gas or liquid inside, the front end of the urine passage is provided with an opening, the guide portion and the air sac are arranged outside the front end of the urine catheter through the opening of the front end of the urine catheter, and the elastic bag body is arranged outside the urine cavity. As that urethral stricture occur, the urethral stricture dilator is moved forward, thenthe elastic bag body is squeeze, the balloon is propped up, the urethral side wall is distracted, the urethral catheter continues to advance, the elastic bag body is loosened, and the operation is repeated, so that the urethral catheter is easy to be inserted.