Abstract: Aiming at the characteristics of farm environmental with measured large area，measured numerous points and long observation time，the farm environmental monitoring system based on the Internet of Things（IOT）was designed.The system was made up of three layers which were sensor layer，transmission layer and application layer，respectively.WSN node hardware circuit based on freescale MC9S12XS128 as microcontroller and node solar photovoltaic power generation system were designed，low layers software system of router and coordinator was programed，communications performance from the remote server to single point and multiple points in WSN was tested.Field experiments showed that the farm environmental monitoring system based on IOT was stable and reliable and provided basis for the scientific forecasting and science cultivation.