The internal flow and spray characteristics for GDI nozzle were investigated by the large eddy simulation (LES) combined with multiphase fluid and spray method. The effects of injection pressure and orifice geometry on the fluid characteristics and droplet size were mainly analyzed. The results show that the increase of injection pressure is beneficial to increase the flow velocity and turbulent kinetic energy at the nozzle outlet and enhance the fuel breakage. The SMD changes little, but the proportion of small droplet increases significantly when the injection pressure is beyond 30 MPa. The flow velocity and turbulent kinetic energy are the largest, the SMD is the smallest and the small droplet ratio is the most at the exit of hyperbolic orifice with the variable section, which is beneficial to improve the spray quality. Compared with the converging nozzle, the turbulent kinetic energy of expanding nozzle is larger at the outlet, which is beneficial to the initial breakup of spray. However, the more cavities block the orifice so as to the low flow velocity, which is not helpful to the fuel secondary breakup.