In order to optimize the indoor environment in large space and improve the attached ventilation theory, a novel ventilation mode, Circular Column Attached Ventilation (CCAV), is proposed. It is found that RSM model simulation could predict CCAV ventilation well by comparing the results of RSM model and experimental data. In this paper, the ventilation efficiency under different supply air velocities and temperatures is simulated and analyzed, respectively. The results show that the influence of supply air velocity on ventilation effectiveness is greater than that of supply air temperature with whose changing only affects the average temperature distribution of the occupied zone. Besides, a higher speed of supply air will lead to draft sensation and reduce ventilation efficiency. Furthermore, the index of ADPI is introduced to optimize the design parameters of supply air. The current results are helpful in understanding a new air distribution—CCAV used for ventilation or air-conditioning system design.