Abstract: For technical requirements of loop heat pipe and heat pipe applied outside connection on low temperature brazing and high temperature using during thermal radiation products,a new type of gallium-based low silver filler metals Ga60Cu38Ag2 was developed. The test resultsanalyzed by scanning electron microscope,DSC,XRD spectrum analysis showed that the elements Cu and Ga in the gallium-based brazing filler metal had formed CuGa₂,and a part of the Ga diffused to the Ag plating of aluminum alloy and forming Ag₃Ga intermediate compound with silver. A Part of the element Al is solid saluted in the coating,and a part formed AlAg₃ intermediate compounds with Ag. The shear strength of brazed joint can reach 18 MPa,and the solidus temperature of solder is 263 ℃,which satisfies the using demand of the expanded heat radiator.