According to the descriptive statistic of wind speed distributing on whole year in east China, the relation of wind load and the opening-angle of the ventilation windows was analyzed and determined, mean while the rectangular distribution weight and fixate of ventilation-windows were briefly calculated. On the based of these, in view of optimized pneumatic ventilation-windows, the expression of cylinder load was derived. Combing pneumatic transfer characteristic, the mechanism fundamental equation of driving moment, driving power, the pressure drop of exhaust and throttle, and movement of ventilation-windows were derived. Adopting nonlinear programming approach and taking these equations as object function, the computerized simulation model of dynamics for the mechanism operation of pneumatic ventilation-windows was established while considering the propriety restrictions. The results of solving this model can give the change process of cylinder load, driving power, angular acceleration, and angular velocity of ventilation-windows with the changes of ventilation-windows position angle.