Abstract: Bolt connection is widely used in the field of construction machinery. Because of the dynamic impact on the bolt interface, there are stiffness and damping at the joint, which makes the characteristic parameters of the bolt dynamic interface nonlinear and highly uncertain. In order to study the dynamic connection characteristics and parameters of bolt dynamic connection interface, an experimental device is designed, using the method of combining finite element analysis with experimental study, the normal tangent stiffness, Surface roughness, medium and damping coefficient of the dynamic connection interface of bolts are studied, the relationship between them is analyzed.