The environment monitoring system of grain depot based on wireless sensor network is designed in order to solve the loss of grains,which is caused by the laggard monitoring technology,and reduce the labor intensity of monitoring staff.The wireless gateway node and monitoring node sensor which is the core of wireless network component are realized by JENIC5139 modules.The temperature and humidity of sample point will be passed to the gateway node by the monitoring node wirelessly.Each gateway node has monitoring alarm functions of fire and smog,and the staff can easily receive timely temperature and humidity data or data records of the grain depot through the host computer software in the monitoring center.The system is effective to reduce food loss,eliminate fire risks of warehouse,and provide reliable research data for the improvement of warehouse storage through long-term accumulated data.