Depressurization and injection-increasing device for water injection well

The utility model provides a depressurization and injection-increasing device for a water injection well, and the device is applied to an oil field water injection well and is used for injecting a surfactant into the water injection well. A high-pressure water injection pipeline is arranged between a water distribution room of the water injection well and the well head of the water injection well; the inlet of a chemical storage box is fixedly provided with a pipeline and the pipeline is sequentially and serially connected with a low-pressure valve, an electric pump and a valve; and depressurization and injection-increasing chemicals can be injected into the chemical storage box through the electric pump. The outlet of the chemical storage box is connected with a liquid discharging pipeline and the liquid discharging pipeline is sequentially connected with a sluice valve, an electric high-pressure proportion chemical adding pump and a single-flow valve; and the other end of the liquid discharging pipeline is communicated with the high-pressure water injection pipeline. The depressurization and injection-increasing device for the water injection well has the effects that the depressurization and injection-increasing chemicals can be continuously injected into the water injection well in certain proportion and the injection pressure of the well head of the water injection well can be reduced; and meanwhile, the injection amount of the electric high-pressure proportion chemical adding pump can be adjusted.