Su Shi was transferred to Xuzhou. The Yellow River burst its banks near Caocun, flooded in Liangshanbo, flooded from Nanqinghe and gathered at the gates of Xuzhou. Rising water will soon be discharged into the city and the walls will be washed away. The rich people in the city are scrambling to escape from the city to take refuge. Su Shi said: "The rich all leave the city, and the people's hearts are shaken. Who will guard the city with me? " As long as I'm here, I won't let the water burst its banks and destroy the city walls. "So he drove the rich back to the city. When Su Shi arrived at Wuwei camp, he called out the pawn head and said, "The river is going to rush into the city. It's urgent. Even the imperial army will try its best for me for the time being. "The commander said," If you don't escape from the flood, we villains should serve you. "So he led the soldiers out of the camp with a cup and built a long dam in the southeast. The dike starts from the circus and ends at the city wall. It rained for a day and a night, and there are only three versions of the intact city wall. Su Shi lives in the city every day, even if he enters the door, he doesn't enter. He sent officials to guard all parts of the city wall and finally saved Xuzhou city. He also asked the court to let those who had been transferred to serve, raise the old city walls and build wooden dikes to prevent floods from coming again. The court adopted his suggestion.