The N00 method is a highly efficient and resource saving mining method, and its key step is to quickly separate the gob roof and the roadway roof by making a slit between them. Based on the water jet theory and technology, a new idea of using abrasive jet directional cutting roof was proposed. The structural composition and working principle of the abrasive jet directional cutting system were studied, and the water jet nozzle, cutting nozzle, orienter, conveyor, abrasive were designed. Through experiments, the working parameters of the abrasive jet directional cutting were optimized. The roof cutting test was carried out on the S1201-Ⅱ working face of a mine in Shaanxi. The results show that under the conditions of jet pressure 25 MPa, nozzle diameter 1.5 mm, abrasive type yellow sand/quartz sand, abrasive mass concentration 3.5% and cutting speed 4.4 mm/s, the developed system is able to make slits at the same time in 4 holes of 7 000-8 000 mm deep within a cycle time (50 min).