With the dynamic constitutive equation of sample structure

perturbation theory is employed to analyze the dynamic characteristics of machine tool based on joint interface

and the influence of the joint interface variation on mass

stiffness and damping matrix is indicated. The influence of machine tool dynamic performance under the perturbation of stiffness is presented with the comparison of the varying stiffness and damping matrices before and after perturbation. Sensitivity analysis of eigenvalue and quantitative optimization design for a beam-moving-type machine tool is carried out

and the impact of the four joint interfaces stiffness to the natural frequency is pointed out and the definitive stiffness value of the guideway joint

which can prompt the machine tool first-order natural frequency from 29 Hz to 35 Hz

is gained. Finite element analysis shows that the error of first-order eigenvalue perturbation method is limited within 5%.