Abstract: In order to explore the scheme of heat treatment to optimize the damping property of arc additive magnesium alloy, stress relief annealing and full annealing for 4 h and 5 h were carried out for TIG arc additive AZ31 magnesium alloy, and the microstructure, damping properties and mechanical properties of the original sample and the annealed samples were compared and analyzed. The results show that compared with the original sample, the damping property of all annealed samples are reduced at low amplitude, when the amplitude exceeds 20 μm, the damping performance is improved. However, the damping property of the stress relief annealed sample is improved less after 20 μm, the damping property of the samples annealed for 4 h and 5 h is similar and higher than that of the original samples, which shows that the annealing time has little effect on the damping property. In terms of mechanical properties, the tensile strength of the stress relief annealed sample and the sample full annealed for 4 h is similar to the original sample, and the tensile strength of the sample after full annealed for 5 h has slightly decreased.The elongation of the sample after stress relief annealing has little difference with that of the original specimen, but the elongation of the sample after full annealing increases.