The invention discloses an Au-Ga brazing filler metal. The Au-Ga brazing filler metal is prepared from the components in percentage by mass: 29%-31% of Ga, 0.001%-0.05% of Ni, 0.001%-0.05% of Al, andthe balance of Au. Market-sold gold ingots, metallic gallium, nickel plates and aluminum plates are used, proportion is conducted according to the design composition, gold and the gallium are arrangedin a graphite crucible, melting is conducted in an intermediate frequency furnace, the intermediate frequency furnace is heated to 1200 DEG C, after the gold and the gallium are totally melted to a uniform liquid, powdered nickel powder and aluminum powder are covered with pure gold foil to add into the uniform liquid, and uniform mixing is conducted. A covering agent, after being optimized, sieved and determined, is added during melting. After casting, rolling and cutting, soldering lugs with required sizes are obtained. The Au-Ga brazing filler metal can be used for packaging of electron devices with high power and high integration density, and particularly used for the connection and packaging of chips.