The invention discloses a method for obtaining mechanical property indexes of a dynamic compaction reinforced soil body of a silt soft soil foundation, and belongs to the technical field of foundationtreatment. According to basic parameters of the silt soft soil foundation, a display dynamics partial differential equation of a rammer and a silt soft soil foundation finite element is established,a central difference method is used for solving, and a normal compressive stress time history, close to the actual situation, of the contact surface of the rammer and the foundation is obtained; then,a foundation soil elastic-plastic kinetic model of the silt soft soil foundation is built; and the normal pressure stress time history of the contact surface of the rammer and the foundation is takenas an external force boundary condition of a finite difference kinetic model of the foundation, and the finite difference kinetic model of the foundation is solved by using a finite difference methodto obtain mechanical property state indexes of foundation soil bodies with different depths in the dynamic compaction process.