The invention discloses a treatment technology of improving corrosion resistance of additive-manufactured titanium alloy, and belongs to the field of metal treatment. Later-period heat treatment is conducted on the basis that chemical method treatment is conducted on the additive-manufactured titanium alloy to remove surface floating powder particles, the solid solution temperature which is characterized in that the heating temperature is lower than or higher than the phase change temperature is adopted to conduct solid solution treatment, aging heat preservation treatment or annealing treatment is adopted and supplemented with different cooling methods such as a water quenching method and an air cooling method, and the organizational structure of the additive-manufactured titanium alloy which is treated in different heat treatment modes is obtained so that the corrosion resistance of the additive-manufactured titanium alloy can be improved. The treatment technology is easy and convenient to operate, effective and free of pollution, an existing additive manufacturing process does not need to be changed, only easy heat treatment needs to be conducted on a titanium alloy part in theafter-treatment process, the follow-up utilization of the titanium alloy workpiece is not affected, and the anti-corrosion capacity of the additive-manufactured titanium alloy in simulated body fluidis improved to range from 22.41% to 36.39%.