The invention discloses a method for manufacturing metal additive materials. The method includes the steps that a part structure and a supporting structure are built layer by layer, wherein the supporting structure is built by using an adhesive agent for bonding metal powder materials; and after part formation is completed, the adhesive agent is melted by high-temperature heating or dissolved by an organic solvent, and the supporting structure is removed. The invention further discloses a device for manufacturing the metal additive materials, and the device is included in the method. The device comprises a high-energy beam source, an optical unit, a forming chamber, a forming cylinder and a powder laying device, wherein the forming cylinder and the powder laying device are located in the forming chamber; the forming chamber is further provided with an adhesive spraying device which is used for providing the adhesive agent needed for building the supporting structure included in the method. The supporting structure built by the adoption of the method and device can be removed only by making the adhesive agent melted with high-temperature heating or dissolved with the organic solvent after part formation is completed, and no subsequent machining treatment is needed, so that cost for the subsequent treatment is reduced, and the forming efficiency is improved.