Straight flute, also known as gap flute. The shape and structure of the Miao fringe air-sounding instrument and the straight-through Xiao are as follows.

The straight-through flute pipe is made of bamboo, which is mostly made of old water bamboo that grows locally and is called "digging" in the Miao language. The tube body has no joints, and both ends are transparent. The tube is 38 cm long, the outer diameter of the upper nozzle is 2.3 cm, the inner diameter is 1.7 cm, and the outer diameter of the lower nozzle is 2.1 cm and the inner diameter is 1.5 cm. During production, on the pipe wall on the front side of the upper mouth, there is a semi-circular notch with a width and a depth of 0.8 cm for blowing holes. The first hole is opened at 6 cm from the mouth, the sixth hole is opened from the upper mouth to 1/2 of the first hole, and the second, third, fourth and fifth holes are equally spaced between the first hole and the sixth hole.