The invention relates to a distributed farmland irrigation facility expense control system. A farmland irrigation facility expense control terminal is in communication connection with distributed devices comprising credit card machines, electric energy meters and external load switches, wherein the electric energy meters are used for acquiring electric energy information of corresponding water pumps, the external load switches are serially arranged on water supply lines of the corresponding water pumps, the farmland irrigation facility expense control terminal is connected with the credit card machines and the electric energy meters in the distributed devices, and the electric energy meters are connected with the corresponding external load switches by control. The system adopts a modular structure, and each portion is an independent device. Compared with a traditional electric meter integrating all functions, the system has the advantage that the influence of other functions on metering function accuracy is reduced. The farmland irrigation facility expense control system is more reasonable in functional framework, data are acquired in a distributed manner and processed and uploaded in a centralized manner, the risk of electric shock of users is greatly reduced by strong and weak electric isolation, and the farmland irrigation facility expense control terminal is a state grid I-type collector function expansion board and can be in seamless butt joint with a current electricity colleting system main station.