A monitoring and controlling system of drip irrigation in cotton field was designed and developed based on ZigBee wireless sensor network technology in order to save water resources and use fertilizer effectively. The system collected soil environment information in realtime through a wireless sensor network. And an adaptive weighted fusion algorithm was used to fuse soil moisture data for each node. According to the fusion data, the control commands were transmitted to the solenoid valve to perform realtime monitoring and automatic irrigation. The proportion of fertilizer injection was set based on irrigation water amount, and different requirements of fertilizer amount and fertilizer concentration at different growth stages of cotton. The flow rate of liquid fertilizer was acquired in realtime by using wireless sensor network, thereby realizing the monitoring of fertilizer amount instantly. Meanwhile, the control commands of solenoid valve were sent according to the amount of fertilizer, thus the integration of water and fertilizer irrigation was accomplished. During operation, the data collected by the sensors could be sent to the host computer through ZigBee wireless network coordinator, which was displayed and stored in realtime. Test results showed that the system could achieve automatic control and detection of irrigation and fertilization in accordance with the design requirements.