Abstract: In view of the impact disaster caused by the hard roof of the coal mine, the oriented fracturing technology of the prefabricated cracks along borehole axial direction is proposed. In this paper, 300 mm×300 mm× 300 mm red sandstone samples were used to carry out the true triaxial hydraulic fracturing physical experiment. The influence of different azimuth angles of prefabricated fractures on the initiation and propagation of hydraulic fracturing fractures is studied. The experimental results show that the cracks of the hydraulic fracturing are deflected from the tip of the prefabricated cracks and form a single crack when prefabricated fractures are in different azimuth angles. With the increase of the azimuth angle of the prefabricated crack, the fracturing pressure increases gradually; when the same deflection angle is reached, the crack extension length decreases and obtains the minimum value at 45 °, after 45 °, the crack extension length first increases and then decreases.