The invention provides a viscoelastic damping material with good conductivity and a preparing method thereof. The viscoelastic damping material with good performance is obtained by reacting a component A and a component B according to the volume ratio of 1:0.8-1:1.1. The component A is a semi-prepolymer synthesized by 50-70 parts of low-functionality-degree polyisocyanate and 20-50 parts of polyether polyol, the component B is prepared from 25-60 parts of a diamine chain extender, 30-65 parts of amine-terminated polyether and conductive carbon nano tubes, wherein the conductive carbon nano tubes are modified carbon nano tubes, and the weight percent of the conductive carbon nano tubes in the viscoelastic damping material is 5.5-7.0%. The viscoelastic damping material with good performance is capable of accurately controlling conductivity mutation of the conductive damping material in a vadose threshold value region. A conductive phase is capable of forming an intact conductive channel and effectively converting electric charges into heat energy to be dissipated, and can achieve certain self-adaptive damping controlling performance.