The invention discloses a raw coal gas purification circulating device and method. The raw coal gas purification circulating device comprises a sediment tank 1, a tar ammonia water collection tank 2, a horizontal water-tube cooler 3, a coal gas water seal tank 4, an electrostatic tar catcher 5, an ammonia water circulating pump 6 and a coal gas fan 7, wherein one end of the coal gas water seal tank 4 communicates with a low-temperature retort furnace through a pipeline, and the other end communicates with the horizontal water-tube cooler 3 through a pipeline; the coal gas water seal tank 4 also communicates with the sediment tank 1 through a pipeline; the sediment tank 1 communicates with the tar ammonia water collection tank 2 through a pipeline; the tar ammonia water collection tank 2 communicates with the ammonia water circulating pump 6 through a pipeline; and the ammonia water circulating pump 6 communicates with a pipeline between the low-temperature retort furnace and the coal gas water seal tank 4. The device can collect and reutilize tar and coal gas generated in the retort process. Compared with the traditional industries, the device disclosed by the invention is environment-friendly and enhances the raw material utilization ratio.