Abstract: The atomization process of two liquid impinging jets has complex interface moving, which is difficult to solve with traditional grid-based methods. In this paper, the problem of two liquid impinging jets and atomization was simulated with three-dimensional Smoothed Particle Hydrodynamics (SPH) method. A simplified model is proposed according to the practical process of two impinging jets and atomization, and a new formula of reference pressure is used to compute state equation. A hybrid expression, combining a standard SPH first derivative with a finite difference approximation of a first derivative, is used to replace the second derivative item in the viscosity, while the parameters in artificial stress are redefined. Compared with experimental results, the simulation results are found to be in good agreement with them. It is proved that this proposed method is suitable to solve the problems of complex interface moving such as liquid impinging jets.