The application of inert dust in paddy storage in the condition of high temperature and high humidity was studied. The new technology to mix inert dust with the paddy of the surface layer (150 mg/kg) and set insect prevention line was compared with common practice grain storage technology. The results indicated that during 19 months, the insect density was 4 head/kg paddy in the treatment warehouse on October 2013, and at that time the fumigation with aluminium phosphide was carried out. There was nearly no insect in the warehouse till April 2014.To the control warehouse, the insect density was 28 head/kg in July 2013, and 24 head/kg in October 2013, and 16 head/kg in April 2014, and three times of fumigations with aluminium phosphide were implemented in corresponding month. So with the application of inert dust the fumigations in treatment warehouse was 2 times less than in the control′s, therefore reduce the grain loss and save labor. No adverse effects on grain quality occurred. So the application of the inert dust in grain storage area presentes good prospects, deserved popularization.