In order to explore the anti-cracking and anti-scouring characteristics of XYY biopolymer modified clay, several cracking and scouring tests were carried out. The test results show that under dry conditions, with the addition of biopolymer, the anti-cracking characteristics of the sample are significantly improved. The addition of biopolymer enhances the tensile strength of the soil, which is greater than the tensile stress of the sample due to drying and dehydration. With the increase of the biopolymer content, the sample changes from cracking to dehydration and shrinkage, the residual moisture content of the sample increases with the increase of the content of biopolymer. The addition of XYY biopolymer enhances the water retention of the soil. After scouring, plain soil samples develops obvious erosion damage traces, and the scouring rate is 49.56%, while the structure of biopolymer improved soil is still relatively complete. When the content of biopolymer reaches 2.0%, the scouring rate of the sample is only 0.81%, indicating that the clay improved by biopolymer has a good anti scouring effect. At the same time, the micro mechanism analysis shows that the XYY biopolymer can effectively fill voids between clay particles, make the clay structure more compact, and effectively improve the anti-cracking and anti-scouring characteristics of clay.