According to legend, during the reign of Emperor Kangxi of the Qing Dynasty, there was a tracker in Tukan who met a businessman from Hunan. The businessman heard that the slopes on both sides of the Wujiang River were planted with sweet potatoes, and the only way to eat them was to cook them. So he told him that the sweet potatoes could be ground into fine pulp, precipitated and made into sweet potato starch to eat. After returning home, the tracker began to learn how to process and make sweet potato starch. He found that the vermicelli was smooth and soft, and it could be eaten in a variety of ways, such as making soup or stir-frying. This changed the situation that sweet potatoes were inconvenient to store and had a relatively simple way of eating. Every year, after the sweet potatoes mature and are dug up, almost every household in the local villagers makes sweet potato starch. Today, Wulong sweet potato starch has become an intangible cultural heritage food with unique Wulong characteristics, and is popular in Chongqing and even all over the country. Making sweet potato starch has also become a pillar industry for local farmers to increase their income and become rich. In 2019, it was included in the sixth batch of representative projects of Chongqing's intangible cultural heritage.