To understand the cooling effect and water loss of different transverse ventilation modes, Cover the grain stack with film and step by step unwinding grain stack film both in the transverse ventilation were used in the two wheat stored warehouses which the wide is 30 m. The temperature and moisture of the grain in the two warehouses before and after ventilation were tested, the uniformity of grain temperature was measured. The cooling effect, unit energy consumption, water loss, temperature and water uniformity were evaluated. The result indicate that: compared with the step by step unwinding grain stack film in the transverse ventilation, although the ventilation time and unit energy consumption of covering the grain stack with film increased by 140 h and 600 kW.h respectively. However, the uniformity of ventilation was better, the cooling effect was slightly better, the cooling range was 0.5 ℃ higher, the grain water loss was small, the average water of the whole barn wass 0.1% smaller. So it provides a basis for the reasonable selection of transverse ventilation.