In view of the problems faced by the application of surface hydraulic fracturing technology in the field of coal mine roof weakening, such as shallow burial depth, complex formation stress, structural development, coal seam fluctuation and adjacent goaf, the key technology and engineering application research of surface hydraulic fracturing technology for weakening thick and hard roof of coal seam were carried out. The results show that: from the perspective of rock structure transformation, the prefabricated joint network destroys the local rock layer, thus reducing the bearing capacity of rock structure; From the point of view of physical property modification, the radiation effect of fracturing injection pressure and elimination of local stress concentration area in the rock layer make the rock layer tend to stress homogeneous state. A fracture target layer identification method based on theoretical calculation and open hole logging measurement is proposed. Based on the formation description and floating collar tool, the high-precision trajectory control and high water sag ratio casing running technology are improved. The directional perforation, efficient temporary plugging and steering technology of fracture network are introduced to realize the direction and scale control of fracture network near the wellbore, and the well ground data fusion analysis method during fracture network dynamic monitoring and recovery is constructed. The engineering practice and application of multi-objective layer vertical wells and shallow buried horizontal wells with large water vertical ratio were carried out respectively to achieve the technical objectives of multi-objective layer dynamic optimization, unilateral temporary plugging and steering of fracture network, accurate control of drilling trajectory between coal seams, casing completion with 2.82 water vertical ratio, fracture network direction and scale control, and formed the ground fracturing weakening technology system of thick and hard roof in coal mine.