Curtain telescopic external member

The utility model belongs to the field of connecting rails, and discloses a curtain telescopic suite which comprises a mother rail, a son rail arranged in the mother rail and a hanging wheel. Notchesare formed in the lower parts of the primary rail and the secondary rail; a pair of outer rails located on the two sides of a notch of the mother rail is arranged on the lower portion of the mother rail. A pair of inner rails matched with the outer rail and positioned on two sides of the notch of the sub-rail are arranged at the lower part of the sub-rail; a first sliding rail is arranged on the edge of the outer rail, and a second sliding rail is arranged on the edge of the inner rail. The hanging wheel slides on the first sliding rail and the second sliding rail along the notches; a pair offirst grooves matched with an external mounting code is formed in the upper part of the sub-rail; supporting pieces used for supporting the first grooves are arranged on the two sides of the upper portion of the inner wall of