The application of transverse ventilation technology for cooling grain in long-span warehouse (3624) was studied. The result showed that the ventilation path was more than four times of that by tradition ventilation, the cold-heat exchange more sufficient, with lower energy consumption. After ventilation the temperature in grain pile was more uniform in grain height direction.The average difference of temperature gradient along the cool air direction was less than 0.3 ℃/m. The cooling efficiency and temperature uniformity was better in long-span warehouse by transverse grain-cooling ventilation technology.