Anti-skid three-joint steel-ball sliding rail

The utility model discloses a return skid prevention three section steel ball slide rail, which comprises an external rail with upper and lower brims; a middle rail with upper and lower brims, which, with the coordination with the upper and lower brims of the external rail via assisting slid piece, can be arranged into the external rail for sliding; an internal rail, which coordinates with the upper and lower brims of the middle rail and can be arranged in the middle rail for sliding; an extruding clamping block is positioned in the external rail; a square hole is positioned at one end of at the preliminary contacting place of the middle and the external rails; a clamping stop piece is positioned on the square hole; when the three section slid rail extends, the clamping block can move into the square hole and prop up to the clamping stop piece. When the middle rail slides back due to external force, the clamping block props to the clamping stop piece, so as to prevent the accidental return slide of slide rail and enhance the safety. Besides, the efficiency for the processing and assembly of the clamping block and clamping stop piece for the utility model can be greatly improved, thus improving the service life of the clamping stop piece and enhance the overall usability of the slide rail.