According to legend, at the end of Sui Dynasty, Yang Guang was dissolute, and listened to rumors to drive Minister Li Yuan out of Chang 'an and demoted him to Jinyang. Tang Gaozu left Chang 'an with his front foot, and Yang Lin, the thief, chased him with his back foot, trying to kill Tang Gaozu's whole family. When chasing Qin, Li Yuan led his son and his entourage to fight bloody battles, and was finally besieged by military forces on Yue Ling Mountain in Qin. When Xu Maogong of Xucun Village at the foot of the mountain heard about it, he led Xucun people to rescue and defeated Yang Lin. After several days of fighting, Tang Gaozu was hungry. When Xu Maogong saw this, he sent someone to cook with a pot, but the pot, bowl and cooker were smashed into tiles. So Xu Maogong asked everyone to set up a stove, pound the mixed dough into small pieces and put them on the pot. They were baked into dry cakes in the stove and given to Tang Gaozu and the soldiers to satisfy their hunger. Tang Gaozu felt fragrant and crisp after eating, so he asked Xu Maogong what the cake was called. Xu Maogong said that this cake is oil-free and salt-free, and it was baked with low fire. I think it's called "dry steamed bread". Therefore, it has spread among the people in Qinxian, Wuxiang and Qinyuan. In the thirty-fifth year of Emperor Kangxi of the Qing Dynasty, when the mother of Wu Wangdian, the senior minister of Yipin Punishment Department, visited him in Beijing, she personally made many dried buns. Wu Ge always sees his mother's hometown specialty. If it is a treasure, he will personally send "dried steamed bread" to the harem for the queen and concubines to taste. After eating, everyone pointed and praised.