In order to solve the roof in the triangle area of the working face of Daliuta Coal mine, during the normal advance of the working face, 52506 working face is taken as the test object, hydraulic precracking technology is adopted, drilling holes are set in the advance working face in the transport chute, and L, S, S‘ three hydraulic precracking drilling layout modes are designed according to the geological conditions. The effect of roof precracking before and after hydraulic precracking, the pressure step distance and the pressure strength were compared and analyzed by field observation. Field observation shows that the hanging roof area of the test section with hydraulic precracking scheme is stable at about 5 m², which is reduced by nearly 80% compared with the non-test section. When the working face advances to the test section, the average pressing step of the cycle reaches 12 m, which is nearly 37 m shorter than the initial pressing step of the non-test section. By comparing the support data of the two sections of roadway during the pressure period, the maximum working resistance of the hydraulic support in the non-test section is concentrated in 60-71 MPa, while the maximum working resistance of the hydraulic support in the test section is reduced to about 48 MPa. It has been proved that hydraulic precracking technology effectively solves the problem of large area hanging roof in triangle area, avoids the roof safety problem during mining, and provides reference experience and technical support for the subsequent cutting operation of adjacent working face.