In this paper, the physical model of the refrigerant two-phase flow through electronic Expansion valve (EEV) was established and numerically solved applying the two-fluid model. The velocity field of vapor and liquid, the distribution of void fraction, and the pressure field of the refrigerant during the throttling were obtained. The curves describing the relationship between the mass flow rate and the pressure difference of the refrigerant were achieved. The computing results agree with the experimental data very well. The mass flow rate- pressure difference relationship of the refrigerant based on these models in this paper can be used in the design of EEV, the research on the match and control of the refrigerating system.