1. General Pressure water distribution in general sprinkler works is mostly done by using motor pumps. Pump electricity accounts for a large proportion of sprinkler operating costs. Therefore, the pump operating efficiency has a great impact on the sprinkler operating costs. Large area of ​​sprinkler irrigation projects are often used pie slice work. The topography of the area, and the pump room distance and the number of nozzles vary, making the pump requirements are not the same. In order for all sprinklers to function properly, the pump is usually selected based on conditions that will satisfy the most adverse pressure conditions. This operating point is generally the normal working point of the pump, that is rated point. For low and close to the pump area is the use of off-valve throttling to adjust the nozzle pressure. This will result in excess head loss on the valve, causing the pump to deviate from an efficient work area, causing a significant amount of energy waste and creating a serious uneconomical operation. For this purpose, speed control technology is adopted to enable the pump to adjust the output characteristics according to the working conditions of different areas and adapt to the working requirements of the nozzle. In addition, the pump can operate efficiently under various operating conditions to achieve the effect of saving electricity and stabilizing pressure. This article only from the pump performance and speed governing principle of pump speed governing technology in sprinkler irrigation project application. 2, pump room condition analysis and pump speed saving principle Water pump in sprinkler works are generally vane pump, vane pump characteristics Q ~ H, Q ~ N, Q ~ η curve represents the head, shaft power, efficiency The relationship with the flow, see Figure 1. In addition the characteristics of the pump working system, often Q ~ G curve. Where H = Hn + Hf, Hf = CQ2, Hn = H net + H spray C - hydraulic coefficient of the pipe from the pump to the nozzle; H net - net head of the pump where the nozzle is located; H spray - working pressure of the nozzle. H = Hh + CQ2 is a quadratic curve through the Hh point, Q ~ H and Q ~ G curve of the intersection A is the normal operating point of the pump, usually the most adverse pressure area work at this point, usually the pump rated point. The pump will operate in the following conditions when a zone other than the normal operating point is enabled. H net decreases, the pump head is higher than the nozzle rated working pressure, the nozzle flow is greater than the rated flow, the pump operating point lower than the normal working point, that is, Q ~ G curve down to Q '~ G' and Q ~ H intersection A 'point. If H net reduction more, the pump will work in the non-efficient area.