There is no bridge over Taihu Lake in Suzhou, and baodai bridge was built in the Tang Dynasty. At that time, Jiangsu and Zhejiang provinces were densely covered with water networks and fishermen, so they were called "Land of Fish and Rice" since ancient times. Therefore, emperors of all dynasties regarded this place as an important place to collect wealth and taxes. In 6 10, the Beijing-Hangzhou Grand Canal was dug, which transported a large amount of grain and treasures from Jiangsu and Zhejiang provinces to Kyoto in the north. In the Tang Dynasty, grain transportation was unprecedentedly busy. A section of the canal from Suzhou to Jiaxing runs north and south. In autumn and winter, it is difficult for cargo ships to go against the northwest wind without carrying fibers.

In addition, there is a gap about 300-400 meters wide at the junction of Lake Dan Tai and the Canal. If the bank is connected with the approach road, it will cut off the passage of Suzhou Lake into the sea through Wusong River, and the bank will be easily washed away by the rushing lake. Therefore, building a bridge here is the best choice.

At that time, Wang Zhongshu, the secretariat of Suzhou, made up his mind to build a bridge here in order to ensure smooth grain transportation. In 8 16, Wang Zhongshu led many skilled craftsmen to start construction, which lasted for four years and finally completed the bridge. Since then, boatmen and people in the past have been greatly facilitated. At the beginning of the bridge construction, due to the financial constraints of the government at that time, Wang Zhongshu generously donated his jade belt to help build the bridge, hence the name of baodai bridge.