Door peg is a connective component which originally joints the middle sill and lian-ying, the connecting column in Chinese traditional house door. Afterward, it gradually becomes an ornament. Door peg originated in “fa-yue”. There exist various shapes of door pegs, such as roundness, square, hexagon, octagon and multivalve. Generally speaking, there are 2 to 4 pegs in a house door. The description methods include plant engraving, relief engraving and concave engraving. And the ornament can be catalogued into picture style, character style and picture-character style. Although the peg illustrates conciseness in style, it shows us abundant contents. By using metaphor and symbolic approach, it demonstrates people's pantheism worship, and reflects people's yearn and pursuit for happy life.