The invention provides a skidded water injection well washing device and process belonging to the technical field of oilfield water injection well washing. According to the technical scheme, the skidded water injection well washing process comprises the steps of supplying power of a well field to the well washing device, reversing a well washing process, and opening a pressure reducing valve; then, slowly starting a water injection well water return process, enabling the return effluent to enter an oil-sludge-water separating tank after reducing the pressure of the return effluent by using the pressure reducing valve, and then, enabling the return effluent to sequentially pass through a multifunctional integrated coarse filtration tank and a multifunctional integrated fine filtration tank; enabling water treated by reference to effluent discharged from an outlet of a three-stage treatment tank to enter a cement truck, and starting the cement truck to do the circular well washing work when the volume of a water tank of the cement truck is up to about 1m<3>; regulating the injection/discharge capacity of the cement truck according to the well washing discharge capacity sequence from small to large, and controlling the normal well washing discharge capacity at more than 25m<3>/h(410L/min); determining that the circular well washing work is ended when the quality of the effluent discharged from the outlet is up to lower than double 20; and restoring the normal water injection of a water injection well after carrying out circular well washing under pressure, and logging the oil pressure and casing pressure at a wellhead.