The Daguang string is composed of a piano barrel, a piano rod, a piano shaft, a piano string, and a bow. The preferred material for making the Daguangxian tube is the rhizome of Taiwan Lintou wood. The appearance of Daguangxian is similar to Fujian Nanyin Erxian. is plugged in.

According to the current internationally accepted "Huo Yisa Musical Instrument Classification", it belongs to "Nail-type stringed board-surface musical instruments". Published in 1993, "Chinese Opera Chronicles·Fujian Volume" records: "Daguangxian, Qin Jian is made of sisal or palm tree rhizomes. The surface is a plane tree with a diameter of fifteen centimeters, a bottom diameter of fourteen centimeters, and the length of the rod. Eighty-six centimeters." According to the author's understanding, the dimensions and specifications of the Daguang strings in actual use are not quite consistent. The author recently measured several pianos in the hands of professional theater troupes, folk artists and luthiers in Xiamen and Zhangzhou.

Except for the basically the same length of the piano slips, there are certain differences in the rest of the data. The reason for this situation is that, in addition to the fact that the specifications of the instrument have not yet been standardized, the manufacturer can do it according to personal preferences (such as the length of the piano rod), and more importantly, it is determined by the sound box (qin) of the instrument. It is determined by the materials used (No. 1 piano in the table is made of brown wood, No. 2, 3, 4, and 5 are made of agave rhizomes). can be clearly seen in . There are three kinds of materials used by Master Wang to make Qin Jian: agave rhizome, palm tree head, and river wood. The shape and characteristics of the qin Jian made of Jiangmu are quite consistent with the production characteristics, while the qin Jian made of agave rhizome or palm tree head has obvious differences. It can be seen that there is nothing to do, and it is impossible to hear. The reasons for this will be described in detail in the production section below.