Abstract: To accurately estimate the drip amount of irrigation and fertilization of citrus, and to realize the remote control of start and end time for drip irrigation by mobile APP, we constructed the water requirement model at different growing stages of citrus in Guilin and conversion algorithm modes between meteorological factors (such as precipitation) and soil weight moisture capacity on the basis of analyzing the citrus phenological period from 1994 to 2015 in Guilin and the meteorological conditions; in addition, we clarified the drip irrigation technology process of citrus, and estimated the amount of drip irrigation in a citrus planting demonstration base of Nanning by applying the model to the drought occurred in March 1997. The results showed that: the model for estimating the amount of drip irrigation could save more than 40% water compared with the traditional model. It has significant reference for building the innovative service mode of“weather monitoring and forecasting information + large- scale production management facilities + feedback and interaction of production information”.