The invention discloses an electronic beam added material manufacturing method of molybdenum base alloy powder. The particle size of the used molybdenum base alloy powder is 55-85 microns; and when powder layers are scanned by electronic beams, a twice scanning mode is adopted. The molybdenum base alloy electronic beam added material manufacturing process finds out manufacturing process parametersof added materials with the highest compactness, and adopts the twice scanning mode to solve the nodulizing and powder splashing problems in the manufacturing of the electronic beam added materials to improve the compactness of components to the casting level.