AlN ceramics and Mo-Ni-Cu alloy were brazed actively by Ag70-Cu28-Ti2 active solder in vacuum. The microstructure and phase composition of the brazed zone were analyzed and its mechanical properties and gas leakage were tested. Results show that Cu content is relatively high in the interface between the solder layer and the alloy; while Ti-rich layer with 1-2 μm thickness forms in the interface between the solder layer and AlN ceramics, where TiN is found by XRD, which indicates that there is chemical bonding in the AlN-solder interface. The gas leakage rate of the sample was 1.0 ×10-11 Pa·m3/s, and the bending strength and shear strength were σｂ=78.55 MPa, and στ=189.58 MP, respectively.