Blowing gas method directly affects the interrupting capability in arc-quenching chamber of puffer SF6 circuit breaker. Aiming at the proposed novel Rotary-Gas nozzle structure of the arc-quenching chamber, finite volume method has been applied to analyze the 3D flow field. Computational fluid dynamic (CFD) simulation for the interrupting process has been performed. The simulation provides the comparison of the distribution of velocity, pressure and density for different structures in flow field. By establishing the Rotary-Gas grooves in the traditional nozzle upstream, the advantage of blowing arc rotation has been analyzed. Hence, by changing the angle and numbers of the Rotary-Gas grooves, the rational nozzle structure has been obtained.