Abstract: In this paper, the effects of heat-treatment on the mechanical properties of the Ni-Be casting alloy are investigated with tensile test、 hardness test、metallographic structure and scanning electron microscopy(SEM). The results show that the mechanical properties are affected largely by aging-time and aging-temperature, and it's found with SEM that there are fine toughness dens on the fracture surface of the Ni-Be alloy. Through different heat treatment processes, three kinds of Ni-Be alloy with different hardness (HRB87、HRC32、HRC51) are obtained, and their comprehesive properties are excellent.