Anti-loose connecting screw, watch band and watch

The utility model provides an anti-loose connecting screw, a watch band and a watch. The connecting screw comprises a screw main body and an annular elastic ring, wherein an external thread is arranged at one end of the screw main body, a through groove for the screw to be convenient to screw is formed in the other end of the screw main body, an annular groove is formed in one end, close to the through groove, of the screw main body, and the annular elastic ring is fixedly arranged in the annular groove. According to the anti-loose connecting screw, the annular elastic ring is arranged at one end of the screw main body. Thus, the annular elastic ring can be extruded into a through hole or a threaded hole along with the screw main body when the screw main body is screwed into the through hole or the threaded hole, a gap between the through hole and the screw main body can be filled with the annular elastic ring, friction between the screw main body and the through hole is greatly improved, the screw main body is prevented from being withdrawn out of the through hole, and the risk that the screw is prone to being loose and falling out is fundamentally avoided. Furthermore, the anti-loose connecting screw needn't be fixed by glue, a coating is avoided, the cost is greatly reduced, and the anti-loose connecting screw is also convenient to disassemble.