There are unified requirements. In this paper, the three-line table generally requires that the upper and lower lines are 1 and 1/2 pounds, and the center line is 1/2 pounds. The three-line table is concise in form, clear in function and easy to read, so it is recommended to be used in scientific papers. Three-line table usually has only three lines: top line, bottom line and column line, in which the top line and bottom line are thick lines and column lines are thin lines, and auxiliary lines can be added if necessary, which is still called three-line table. The elements of three-line table include: preface, title, item column, text and comments.