The invention provides an identification method of dynamic parameters of a machine tool fixed joint part. The method comprises the following steps: taking a structural damping matrix of a joint part unit and a stiffness matrix of the joint part unit as parametric variables, setting the difference between the product of a displacement impedance matrix and a displacement frequency response functionand a unit matrix to be minimum as an optimum design objective, and obtaining parameter variable values (i.e., the identified parameters of the joint part) through multiple iteration. The identification method takes damping and stiffness of multiple key freedom directions and the intercoupling relation into account to avoid a secondary error produced by matrix inversion, has high precision, and more accurately characterizes richer dynamic characteristics of the joint part.