The invention relates to a dust-containing high-temperature oil gas washing system and method. The washing system comprises a washing tower, and a washing gas introduction pipe is connected to the side wall of the washing tower; the washing system is characterized in that the washing tower comprises a lower washing zone, a middle cooling zone and an upper defoaming zone; the introduction pipe is connected with the washing zone, an upper partition plate and a lower partition plate which are parallel to each other are arranged at the upper end and the lower end of the cooling zone respectively, and the side wall of the cooling zone is provided with a shell pass inlet and a shell pass outlet which are used for being connected with an outside heat exchange medium; multiple heat exchange tubes are arranged in the cooling zone, and an inlet and an outlet of each heat exchange tube are communicated with the washing zone and the defoaming zone respectively; a defoamer is arranged in the defoaming zone, an oil discharge pipe is connected to the bottom of the washing tower, and an exhaust pipe is connected to the top of the washing tower. According to the dust-containing high-temperature oil gas washing system and method, bubbling is conducted in heavy oil at the bottom of the cooling tower to remove coal ash carried by the heavy oil, vaporization latent heat of boiler water is utilized for cooling high-temperature oil gas, separation of dust, heavy oil and light oil gas in mixed gas is achieved, by-product steam is obtained through the device, and energy saving and consumption reducing are achieved.