The Smoothed Particle Hydrodynamics(SPH)method has been widely used in the simulation of geohazards with large deformation. However, as a particle method, SPH analysis is usually time consuming for the case with a lot of particles. Thus it is essential to conduct the study on the efficiency improvement of SPH method. Here, we propose a 3D SPH model for the analysis of soil flowing based on the principles of SPH method, non Newtonian fluid theory and the concept of equivalent viscosity. Then, the parallel implementation of this model is conducted using the OpenMP framework. For a model test of flowing granular soil, the 2D and 3D simulations are conducted with the proposed SPH model. The comparisons of flowing distance and impact force indicate that both the boundary effect and viscosity effect in the 3D cases are larger than those in the 2D cases, which can cause the decreasing of flowing distance and impact force. Meanwhile, by comparing the speed up ratios under different number of threads, we found that the efficiency has been greatly improved. The proposed SPH model can achieve a good simulation of flowing soil and make the best use of multi-core technology of modern computers. The paper can provide a potential reference to other numerical methods in engineering geology.