Abstract:This paper studies the damping vibration properties of the big damping bar by the generalized multisymplectic method based on the Bridges’s multisymplectic method and the Hamilton variation principle. Introducing orthogonal momenta, a firstorder approximate symplectic form, named generalized multisymplectic form is derived from the control equation of the big damping bar vibration firstly. And then a midpoint Box generalized multisymplectic scheme is constructed by the midpoint method; Finally, the dissipation effect of the big damping bar vibration is studied. From the results of the numerical experiment, the good properties of the generalized multisymplectic method are verified: satisfying the conservative properties of the system and reproducing the dissipation effect of the system.