This paper has developed an axisymmetric laminar and turbulent two-phase flow solver to simulate pressure swirl atomizer. Equations include explicit algebraic Reynolds stress model, Reynolds averaged Navier Stokes and level set equation. Applying high order compact upwind finite difference scheme with the level set equation being culminated to capture the interface between air-liquid two-phase flow and decreasing the mass conservation error in the level set equation. The results show that close to swirl chamber wall and to axis, some recirculation zones are observed. Converting Rankin vortex from the swirl chamber to forced vortex in orifice section can be predicted by this model. The proposal model shows a considerable improvement in the numerical results especially in laminar flow so that the discharge coefficient, film thickness, and spray cone angle are satisfactory with the previous experimental data. In addition, the error is less than 10 percent.