Abstract: The tensile mechanical properties of AlNi₃ were studied by molecular dynamics method. First, the influence of 300 K and constant engineering strain rate on the tensile properties of AlNi₃ was simulated, and the influence of different temperature and strain rate on the tensile properties of AlNi₃ was investigated. The tensile process of AlNi₃ with prefabricated voids was simulated at 300 K to investigate the influence of different void radius and number on the tensile properties. The results show that the stress of AlNi₃ reaches a peak value of 23.397 GPa when the strain is 0.134 2, and the stress of AlNi₃ with voids reaches the peak value of 21.047 GPa when the strain is 0.109 6. With increasing temperature, elastic modulus and tensile strength of AlNi₃ decrease. Furthermore, increasing the strain rate can increase the tensile strength, but has no impact on the elastic modulus. Increasing the void radius and the number of voids can reduce the tensile strength significantly.