Abstract: A modular, multifunctional water valve controller has a first housing and a second housing drawably assembled to each other. The first housing defines a batter room, and receives a driver and a valve of a control circuit therein. A water path is defined at a bottom of the first housing. The water path has an input tie-in at an end thereof, an output tie-in at an opposite end thereof, and a spherical valve on a center thereof. A motor of the driver drives decelerating gears to control start-up or stop of the spherical valve. The control circuit includes a microprocessor, a plurality of operation keys, and three types of modules in the microprocessor. The modules have interval modules, watering modules and action modules. In use, the watering time and interval time or immediate time is predetermined via operation keys and is shown by an LED module. The water valve controller of the present invention has simple type, professional type and system type.