The invention discloses an anti-blocking catheter. The anti-blocking catheter comprises an external pipe, an evacuating catheter, an air inlet pipe, air bags, an internal pipe, a hollow round head and an adhesive tape fixing wing plate, an opening is formed in the upper end of the external pipe, a gap is formed between the inner wall of the external pipe and the outer wall of the internal pipe, a urine catheterization channel is formed, an air inlet pipe is arranged on a pipe body of the external pipe, the multiple air bags connected with the air inlet pipe are arranged on the outer side of the external pipe, the hollow round head communicated with the internal pipe is arranged at an upper end opening of the internal pipe, multiple spray orifices are formed in the top of the hollow round head, the hollow round head is located at an opening, and a drainage opening is formed in the gap between the opening and the hollow round head. The anti-blocking catheter is reasonable in structural design, the phenomenon that the drainage opening is blocked can be effectively prevented, the air bag inflation condition can be mastered at any time, and the phenomenon that the user doesn't know that the air bags leak, and then damage is caused is avoided; meanwhile, the insertion length can be mastered clearly, fixation is firmer, operation is easy, and use is convenient.