The invention discloses brazing filler metal for vacuum brazing of high-nitrogen steel. The brazing filler metal for vacuum brazing of the high-nitrogen steel is composed of, by weight, 25-28 parts ofPd, 39-46 parts of Ni, 36-39 parts of Cr, 2.8-5.8 parts of vanadium plated nickel graphene, 12-15 parts of Mn, 7-11 parts of Re, 6-9 parts of Si and 2-5.5 parts of B. During preparation, a method comprises the following steps that firstly, distilled water, a water-based binding agent, acetone and ethyl alcohol are weighed, raw material alloy powder of the Pd, the Ni, the Cr, the vanadium plated nickel graphene, the Mn, the Re, the Si and the B is prepared according to the proportion and is ground to 106 micons-150 microns to be used; secondly, the acetone, the ethyl alcohol, the water-based binding agent and the distilled water which are obtained in the first step are arranged in a beaker and stirred, and a solution without sediment is obtained; and thirdly, 45-70 parts of the raw material alloy powder obtained in the first step is taken, 12-18 parts of an auxiliary additive is added into the 45-70 parts of the raw material alloy powder, a mixture is added into the solution obtained in the second step, stirring and vacuumizing are carried out, and the pasty brazing filler metal is prepared. According to the brazing filler metal, during brazing, the defect that in traditional welding, air holes are prone to being generated is overcome, the element of nitrogen is almost not lost, and the structure homogeneity of the high-nitrogen steel base metal is guaranteed.