Abstract: To realize automatic control of integral control of water and fertilization under drip irrigation for citrus with independent water tank and liquid fertilizer tank, a timing control device powered with battery for controlling drip irrigation and fertigation was developed. The device was composed of two solenoid valves which were used to control the order and time of water or liquid fertilizer flowing into the drip irrigation pipe network respectively. To extend battery life, sleep mechanism and power management technology were used with the quiescent current of the device less than 11.2 μA. The device was tested in actual application for six consecutive months, and the results showed that the controller was stable and reliable, and the battery voltage dropped only from the initial value of 9.35 to 8.50 V. The device was simple to use, and it can control not only the drip irrigation integration of water and fertilizer, but water drip irrigation. In addition, the rotation irrigation can be carried out by combining multiple devices, and then can control a larger irrigation area. So the device developed in this research is practical and has good promotion prospects.