In view of the existing problems such as long processing process, large area and poor operation effect,the project proposes the underground direct filtration treatment technology and equipment based on organometer-rolled ultrafiltration membrane, and conducted pilot study in a coal mine in NingDong area. The results show that under the condition of low flux, the direct filtration system runs stably, there is no obvious membrane contamination, and the membrane flux decays less than 3%. When the initial flux was 47.4 L/(m2·h) and the recovery rate was 84.6%, the flux decreased by 9.01% after 48 days of operation. The attenuation of membrane flux was mainly caused by membrane pollution caused by cake deposition. At the same time, under the constant pressure operation mode, the recovery rate of the direct filtration system is improved, and the water intake decreases with the increase of water production. In the influent turbidity range of 10~30 NTU, the water quality of direct filtration system is relatively stable, and the turbidity of water production is lower than 0.5 NTU. The overall operation results show that the direct filtration technology has the advantages of short treatment process, stable water quality and strong anti-pollution performance, and has obvious application advantages in underground.