Abstract: Liquefication can be induced by seism and cyclic other loading action in sand ground，which would lead catastrophic damages． Correlational studies have great significance to the engineering and theory． The study was attempted to improve sandy soil by the novel MICP technology and to conduct consolidated undrained triaxial tests as well as dynamic triaxial tests to study the mechanical properties，which showed that the existence of microbially induced carbonate precipitation could improve the strength resisting liquefaction of sandy soil． Numerical simulation was carried out based on the TTS constitutive model，proving that model could describe the constitutive relation for both sandy soil and the one improved by MICP in the unit scale．