The shape is similar to the Han Sanxian, which is composed of a resonance box, a headstock, a piano rod, a peg, a piano horse and a string.

The specifications and sizes of the Yi Xiaosanxian vary, and the total length of the piano is 50 cm to 70 cm. The resonance box (qin drum) is mostly oblate, but it is not a perfect circle, but slightly rounder than an oval shape. The piano frame is mostly made of four pieces of rosewood, walnut, cherry, tea wood, nanmu or other hardwood boards. There are square holes for inserting the piano rod up and down, the two sides are covered with python skin or sheepskin, the skin surface is fixed with bamboo nails, and the thick pig glue is firmly glued.

The diameter of the piano box is 9.2 cm to 16 cm and the thickness is 4.5 cm to 8 cm. The headstock is mostly flat shovel-shaped, the upper part is wider and thicker, and is bent at a 45° angle backwards and upwards.

There is a string groove in the middle of the lower part of the headstock, and there are three hardwood pegs on both sides (left one and right two), which are mostly bud-shaped or conical, with a shaft length of 9 cm to 14 cm. decoration.

The piano bar is wider, it is a semi-circular cylindrical body, the front is flat and the back is round, the front is a fretboard, and there is no grade.

The qin horse is in the shape of a bridge and is made of hardwoods such as boxwood. The horse is 3 cm long and 1.5 cm high, and is placed in the center of the frontal membrane. Zhang Yi has three strings. In the past, the folk used horsetail strings or gut strings, but now they mostly use silk or steel strings. Between the pegs and the tail post of the piano body, there is also a colorful silk strap.