Abstract: In order to clarify the influence of grain size,density and velocity of abrasive material on the erosion rate of abrasive gas jet,the coupling relationship of abrasive particle size,density and gas pressure to abrasive velocity were determined by Fluent numerical analysis,and the abrasive velocity calculation model was established by calculating the equation. Based on the calculation model of abrasive velocity and the theory of elastic-plastic indentation fracture,a single abrasive erosion volume calculation model and the calculation model of abrasive jet erosion wear rate considering the time factor were established. By comparing and analyzing the results of high pressure abrasive gas jet rocking ex- periment and the theoretical calculation result,the model has been modified. Combined with the theoretical analysis and experimental results,under the condition of fixed gas pressure,the erosion rate increases and then decreases with the increases of particle size and density. The effect of particle size on the erosion rate is more significant than that of the density. When the gas pressure is 20 MPa,the 80 mesh garnet is the optimal abrasive in common use of abrasive types and particle sizes. The model of corrected erosion rate calculated is simple and with the consideration of the ener- gy conversion efficiency of abrasive and the effects of breakage of abrasive model on erosion rate calculation. The mod- el and experimental results have good consistency and can guide the engineering practice of high pressure abrasive jet.