Guide thread leading-in device

The utility model relates to a wire guider, which comprises a jacket, a first movable jacket, a second movable jacket, a movable cylinder, an expansion needle tube and a puncture needle tube; wherein, the first movable jacket is sleeved in the jacket, the second movable jacket is sleeved in the first movable jacket, the movable cylinder is sleeved in the second movable jacket, s topper is respectively arranged at the outlets of the jacket, the first movable jacket and the second movable jacket, a stopping platform is respectively on the external walls of the first movable jacket, the second movable jacket and the movable cylinder correspondingly, a clamping piece which makes the first movable jacket and the second movable jacket move together are positioned between the first movable jacket and the second movable jacket, the puncture needle tube is connected with the movable cylinder, a blood returning hole which is communicated with the internal chamber of the jacket is arranged on the wall of the movable cylinder, a seal ring is arranged at the external output of the movable cylinder, a seal ring is also arranged between the expansion needle tube and the jacket, and the puncture needle tube is threaded through the seal ring. The length of the structure is shortened greatly, the part of the assistant needle cylinder is omitted, the materials are saved and the cost is largely reduced, so that the utility model is quite convenient in operation.