Abstract: Numerical fracture induced by neighbor particles moving out of the influencing domain of the kernel function may occur in the numerical simulation of hypervelocity impact problems by the standard SPH method. A new adaptive SPH method by adding and merging particles according to the distance between particles was developed to eliminate the numerical fracture. Numerical simulations were carried out on the Taylor and hypervelocity impact samples. Simulated results display that the new adaptive SPH method can effectively eliminate the numerical fracture in the computation and remarkably improve the computational precision.