<p>Aiming to optimize the performance of low-silver Ag35CuZn silver-based brazing filler metal, the different amounts of Ni element are added to adjust the phase compositions and microstructure in this paper. With the content of Ni increasing, the phase compositions of Ag35CuZn-<i>x</i>Ni brazing filler metals changes from Ag(s.s) phase and CuZn phase to Ag(s.s) phase and (Cu, Ni, Zn) solid solution phase. The needle-like structure gradually disappears, the black structure precipitates and aggregates, and then changes from coarse dendritic distribution to small island distribution. The solidus and liquidus temperatures and melting range of the brazing filler metal first decrease and then increase. However, the microhardness gradually decreases, then remains unchanged, and finally achieves at about 145&#xa0;HV. As the Ni content is 3 wt.%, CuZn phase completely transforms, the needle-like structure disappears, and the brazing filler metal melting range reduces to a minimum of 7.7&#xa0;°C. When the Ni content reaches 5 wt.%, the spreading area reaches its maximum value of 4.96&#xa0;cm², which is an increase of 155%. These findings have significant guiding implications for enhancing the performance of brazing filler metals and developing new low-silver brazing filler metals.</p>