The present invention relates to a twin-trough channel connecting percutaneous pedicle screw inner fixing system, which comprises a twin-trough channel connecting pedicle screw, a connecting rod and aplug screw. The twin-trough channel connecting pedicle screw comprises a pedicle screw and a double-trough connecting channel. The twin-trough connecting channel is a hollow tube and one side of thetube wall is provided with a whole rabbet; the internal side of two thirds tube wall above the opposite side is provided with a groove and the one third tube wall below is provided with an inverted U-shaped semi-rabbet; when the connecting channel is completely connected with the screw, the two rabbets are superimposed; the connecting channel is connected with the pipe interface of the pedicle screw head through screw threaded covered joint, cutting grafting, clamped joint or a long needle axial fixed connecting structure and is provided with an internal screw thread on the lower one second section inside the channel, which is connected with the internal screw thread of the tube joint of the screw head. The present invention adopts the integrated design of the twin-trough work channel andthe screw, thus avoiding multiple replacement of expansion channel, reducing the damages of the approach tissue caused by multiple entering, simplifying the operational machinery and shortening the operation time.