Numerical simulation and analysis of flow field around a simplified fastback car and aerodynamic noise at some receiving point were conducted using CFD software FLUENT. The pulsating flow field was simulated by the large eddy turbulence model and the momentum equations were discretized with the unbounded central difference scheme. The calculations were performed under three conditions: uniform motion with two running speeds and accelerated motion. The influences of pulsating flow field and aerodynamic noise by uniform motion speed, uniform and accelerated motions were investigated. The results show that with the increase of uniform motion speed, the velocity, sound pressure level corresponding to each frequency and total sound pressure level at the receiving point become bigger, the pressure becomes smaller; At the same motion speed, the velocity, sound pressure level corresponding to each frequency and total sound pressure level in accelerated motion are greater than those in uniform motion, the pressure is smaller.