Mechanical ventilation is an important way to maintain the temperature and moisture of grain piles in the warehouse within the safe storage range, which is closely related to grain storage safety and the benefits of storage enterprises. In order to solve the disadvantages of the slow advancing speed of the inlet air in the vertical direction of the traditional Gui-shaped ventilation network, this paper proposed a new ventilation network with Gui-shaped and vertical riser to shorten the travel path and time of air or fumigation gas in the grain pile. The new ventilation network effects through numerical simulation were simulated and predicted to verify its feasibility. The results showed that the cooling rate and uniformity of this ventilation network were good, and the flow resistance of the inlet air in the vertical direction was significantly reduced. The cold front at the position of the riser could pass through the grain surface with a height of 5.5 m on the second day of ventilation, and the ventilation energy consumption could be reduced by about 16% compared with the traditional Gui-shaped ventilation network under the same conditions. The results could provide theory basis for the selection of optimal ventilation network of room type warehouse.