Uses CFD software to simulate and calculate the underfloor air supply of a data room. The results show that the temperature distribution of the data room is relatively uniform, and most areas are 295~296 K; The inner air flow organization is fine, there is no obvious vortex area and ventilation dead angle, and meets the design requirements of indoor air conditioning of information database room. Thus proves that using underfloor air supply system to cooling information data room can effectively improve the room local overheating, providing reference for air conditioning design of similar information rooms.