People often say that "the swan geese pass the book" comes from the historical story of Su Wu's sheep herding. Biography of Hongyan comes from the historical story of Su Wu's sheep herding, and comes from Biography of Su Wu. This story tells the story that the Huns lied that Su Wu was dead and refused to release Su Wu to return to the Han Dynasty. The messenger of the Han Dynasty successfully deceived the Huns to release Su Wu on the grounds that "Emperor Zhao Han shot a goose and received a letter from Su Wu". Shepherd in Suwu is a traditional Shaanxi opera and a true historical story. It tells the story that Su Wu, the minister of the Western Han Dynasty, was sent to Xiongnu by Emperor Wu of the Han Dynasty, but was detained for some reason and suffered all kinds of hardships, but he always adhered to his faith and refused to yield. In extremely difficult circumstances, Su Wu would rather die than surrender to Xiongnu, showing a high degree of patriotism and unswerving loyalty.