The utility model discloses a sewage cleaning device for an oil pumping unit. The sewage cleaning device for the oil pumping unit is composed of a normal temperature water tank, an electric heater, a high-pressure cleaning pump, a spraying gun and a power distribution box. The normal temperature water tank, the electric heater, the high-pressure cleaning pump and the power distribution box are all arranged on a transportation vehicle. The normal temperature water tank is communicated with the electric heater, the electric heater is communicated with the high-pressure cleaning pump, and the spraying gun is communicated with the high-pressure cleaning pump through a hose. An output lead of the power distribution box is electrically connected with the electric heater and the high-pressure cleaning pump. The sewage cleaning device for the oil pumping unit is in a vehicle-mounted mode, operation strength is small, the cleaning time is short, and the efficiency is high. The time rate of an oil well is improved, and the phenomenon that the oil yield of the oil well is influenced due to cleaning of the oil pumping unit is reduced. Safety accidents probably caused by using inflammable materials in a traditional method are removed, and labor intensity is reduced.