The big sanxian is composed of the resonator, headstock, piano rod, peg, bridge, tied strings and strings, etc. The specifications and sizes are different, and the overall length of the piano body is mostly 130 cm to 140 cm. The total length of the piano body can reach 180 cm to 200 cm.

piano
It is cylindrical in shape and large in size. The length of the cylinder is 30 cm to 40 cm and the diameter of the cylinder is 25 cm to 35 cm. The folk extra-large sanxian has a cylinder length of 70 cm to 80 cm and a cylinder diameter of 60 cm to 70 cm. The cylinder cavity is made of pine, pine, fir, paulownia or other lighter woods. The cavity can be dug out from a whole piece of logs, or it can be made by splicing and gluing multiple pieces of wood. There is a square hole that penetrates into the piano rod, the front of the barrel is covered with sheepskin, and the back of the barrel is open without a sound window.

headstock, stem
It is made of a whole piece of slightly harder wood, and local wax gourd or panzhihua trees are mostly used. The shape of the headstock is simple and simple, the upper part is narrow at the bottom and wide at the upper part, the top is in the shape of a scroll and curved backward, and the center of the front is often engraved with red five stars, inlaid round wood carvings or small shiny round mirrors. There is a bottom string groove in the middle of the lower part of the headstock, and there are three pegs on both sides (left one and right two).

peg
It is made of wood with fine texture, such as red toon, rosewood or boxwood, which is harder than the piano rod. The surface of the shaft is carved with twist-shaped or straight petal patterns.

The piano bar is a semi-circular cylindrical body, narrow at the top and wide at the bottom, flat at the front and round at the back. The front is a fretboard with no frets. The upper end is provided with a mountain port to connect with the headstock, and the lower end is inserted into the square hole of the piano barrel. For some fine sanxian, a hardwood fingerboard is often glued on the front of the piano bar, mostly ebony, red sandalwood, mahogany or red toon. The thickness of the fingerboard is 1.2 cm to 1.5 cm. The rod is wear-resistant and not easily deformed.

The qin horse is made of hardwood or old bamboo. It is a long solid horse with an isosceles triangle in cross section. It is placed in the upper center of the membrane surface of the qin barrel.

strings, strings
Zhang three silk strings or beef tendon strings, the lower end of the string is fastened in the string hole of the binding string, the binding string is made of metal sheet, and there are several small iron pieces or small iron rings hanging on it. The musical action made a rhythmic beeping sound. Between the string groove of the body and the tail post, there is a silk-colored strap. Above the string groove, there is also a large red flower made of thin silk as a decoration.