Numerical simulation was performed for the 2-dimensional flow field and temperature in steam plasma reactor. The major equation considered in this study was mass continuity equation, momentum and energy conservation equation and current continuity equation, for calculation of characteristics distribution of velocity, plasma temperature and current density. The flow was solved using k-ε turbulence model. When the steam gas flow of plasma torch are increased, the calculation show that the temperature and gas flow in gasification chamber are increased at the z-axis, but their profiles are constricted radially, and velocity and mass flux are increased, Therefore, the steam plasma jet is expected to provide sufficient to evaporate and, pyrolize plastic waste by staying for a long time in gasification chamber.