Li-B Alloy is one kind of thermal battery anode materials with excellent performance but hard to use due to their preparation limits. A scale of 300 g per furnace was achieved by improving the temperature control, cooling system, stirring blade and so on. The alloy prepared by this method was uniform and compact with a density of 0.870 g/cm3, and a tensile strength of 12.61 MPa. The synthesis mechanism and kinetics process were analyzed according to the physical phenomenon as well as XRD results.