To investigate the insecticidal and protective effectiveness of sulfuryl fluoride fumigation in brick silos, three warehouses with different air-tightness were used for evaluation by analyzing gas uniformity, concentration retention time and insecticidal effects. Whole warehouse non-circulation fumigation and circulation fumigation were adopted with different fumigation concentrations applied. The experiment results show that sulfuryl fluoride gas can naturally diffuse thoroughly through a 10 m grain pile within 4 hours, and achieve uniform gas in the entire warehouse within 24 hours. However, circulation fumigation caused a large amount of chemical loss and the concentration retention time was comparatively short. Results also prove the concentration of 5 g/m3 can achieve a desired and rapid killing effect of 4 main types of pests in stored grains.