For wiring difficulties and poor mobility problems of temperature and humidity, dew point, and other measuring instruments in agro meteorological monitoring, a temperature and humidity node is designed based on WSN, which is constituted by the high precision temperature and humidity sensor SHT75, CC2530 wireless processor, SD2003A clock chip, GPS module TU 30, and other circuits, and the peripheral circuit design of each functional module is completed. Using the Zigbee protocol for networking, after the testing procedures of temperature and humidity, the node sends the data to the network through wireless. This node can be used as a network node arranged in different positions in farmlands, greenhouses or granary, constructing the monitoring system for agricultural services together with other meteorological network nodes and achieving the measurement of temperature, humidity, etc.