The invention relates to a downhole device using hydraulic jets of parallel tubes to flush pulverized coal for the field of development of a gas field and a coal-bed gas field. The downhole device consists of a throat diffusion tube 1, an outer cylinder 2, O-shaped sealing rings 3 and 9, a high-pressure nozzle 4, copper washers 5 and 11, a high-pressure chamber 6, a sleeve 7, sand flushing teeth 8, a mixing nozzle 12 and a guide connector 10. The guide connector 10 is connected with the high-pressure chamber 6 in a welding way; the internal circular surfaces of the upper end and the lower end of the high-pressure chamber 6 are respectively connected with the high-pressure nozzle 4 and the mixing nozzle 12 via threads; the internal circular surfaces of the upper end and the lower end of the outer cylinder 2 are respectively connected with the external circular surfaces of the throat diffusion tube 1 and the high-pressure chamber 6 through threads; and the sleeve 2 is connected with the sand flushing teeth 8 in a welding way and connected with the high-pressure chamber 6 through threads. The structure of the device is simple, part of power liquid is used for exerting impact on downhole pulverized coal so that the pulverized coal is fully mixed with formation fluid; and the rest of power liquid is sprayed by the high-pressure nozzle to form a negative pressure area, the formation liquid is sucked in a rolling way after being mixed into a returning liquid tube, and thus the downhole pulverized coal can be discharged.