Drainage tube structure convenient to replace

The drainage tube structure convenient to replace comprises a drainage tube body and an inner sleeve, one end of the drainage tube body is provided with a drainage head extending into an affected part, the other end of the drainage tube body is provided with a connecting assembly, a drainage main cavity is formed in the drainage tube body, and a drainage opening communicated with the drainage main cavity is formed in the drainage head; the connecting assembly is connected with an external drainage liquid collecting device, and the drainage main cavity is communicated with the external drainage liquid collecting device through the connecting assembly. The inner sleeve is embedded in the drainage main cavity, an elastic first supporting core is arranged in the inner sleeve, a mounting cavity for allowing the first supporting core to be inserted is formed in the inner sleeve, an elastic guide core is arranged in the first supporting core, and a guide cavity for allowing the guide core to be inserted is formed in