A method for preparing nonferrous metal by vacuum thermal recovery belongs to the vacuum metallurgy field. The process steps include: reduction material, reducing agent and assistant are firstly prepared according to chemometry of reduction reaction and then mixed with grinding mills and fed into a vacuum ball milling tank, heating is carried out and the reaction system is ball milled, and vacuumthermal reduction reaction under ball milling is carried out, so as to obtain metal steam and obtain condensed metal by condensation. The metal preparation method is short in process route, low in energy consumption and high in yield and is high-efficiency and energy-saving.