This paper mainly studies at the different way of ventilation to the influence of air distribution in the large size plenum. The model is a grand theatre stalls. To model the plenum which under the grand theatre stalls,and took out the size of large mutations alone modeling and studying it. the six different way of ventilation: small plenum with four directions supply air; Take a duct with four tuyere on supply air; Single tuyere withside air supply; Tuyere parallel supply air; Single tuyere with air supply under; Take a duct with four draught under supply air have influence of air distribution.And combined with the well of heat insulation in the large size plenum.It can use the standard RNG turbulence model, and the pressure interpolation adopt standard discrete format, the convection item of the momentum equations, k equation, ε equation adopt with second order the format. the pressure speed coupling adopt Simple algorithm. Finally through the FLUENT software were used. It can use the air balance coefficient wich is one evaluation index to analyz Simulation results of the Six air distribution mode . Through the analysis and comparison with a wind that four tuyere air supply under Static pressure boxair supply the best effect, the static pressure air distribution most evenly