The insecticidal effect of domestic developed mobile duster and food-grade inert dust on five major species of stored grain imago, Rhizopertha dominica (Fabricius)，Sitophilus zeamais (Motschulsky)，Oryzaephilus surinamensis (Linné)，Tribolium castaneum (Herbst)，Cryptolestes ferrugineus（Stephens）, operating empty grain storehouse, was tested in order to solve the problems, such as poor effect，insect resistance，and harm to operators. The results showed that the duster possessed good spraying effect with uniform dispersion of dust without obvious difference inside of the grain storehouse, the mortality rate of the store pests in the test reached 100% in 3 days．