Abstract: In order to solve the problems such as low efficiency, large deviation of drilling angle adjustment and poor directness of drilling in roof pre-splitting drilling technology, ZDY2-300LM slot-cutting drill was developed. The key technologies and design points of the structure layout, car body platform, angle adjusting device, and construction drilling tools, waterway system and hydraulic system of slit drilling rig are studied. According to the type test, no-load test and load test are carried out respectively, and the results show that the indexes of the drill meet the design requirements. Through three underground coal mine tests, the cumulative drilling footage of nearly 50 000 m, the test shows that: drilling rig meets roof pre-splitting hole construction requirements by roof cutting pressure relief mining technology without pillar, and has obtained the good effect of cutting roof pressure relief, effectively solves the roof pre-splitting hole construction lack of dedicated, reliable equipment problems; moreover, the drilling machine has the characteristics of efficient construction, wide adjustment range of hole spacing, more adjustment of borehole angle parameters, narrow fuselage and better borehole protection.