The theoretical study of a threedegreeoffreedom main system with dynamic vibration absorber was carried out.First,according to the threedegreeoffreedom system simplified model,the analytic expression of the force transfer rate was deduced based on the superposition principle of the differential equation;secondly, the analytic expression of the force transfer rate of the system with dynamic vibration absorber was obtained; finally, according to the formula, the influences of the mass ratio, the natural frequency ratio and the damping ratio on the force transfer rate were analyzed, the influence law of the structural parameters of the vibration absorber was obtained, and the parameter selection problem of the dynamic vibration absorber for the threedegreeoffreedom main system was solved.It provides a reference for study on dynamic vibration absorber for the multidegreeoffreedom main system.