A new type controllable damping-viscous damper is designed and manufactured,at present it's impossible to proceed computational analysis by available softwares. In this paper the structural dynamic equations of MDOFsystem sturetures with supplemental controllable damping-viscous damper are created,a practicable analysis method is proposed,the solution of time history method is deduced. A corresponding program is completed by Matlab languages; the results of calculations with some examples shows that the effect of vibration absorption is remarkable,especially for the high and supple MDOF-system sturetures with supplemental controllable damping-viscous damper.