In order to complete the initial roofing of the hard roof with expanded surface by adopting the new technology of abrasive jet axis roofing, the key technical parameters of axial roofing and fracturing of abrasive jet were determined through field industrial tests in Kuangou Coal Mine, and the initial roofing scheme and project of axial roofing of abrasive jet with expanded surface were designed and carried out. The implementation process is monitored by means of hydrometer, drilling peeping and on-site observation of water discharge, and the effect of mining process is tested by means of microseismic monitoring, support pressure monitoring, coal body stress monitoring and roof caving observation. The research results show that the industrial test of prefabrication of 300mm deep fractures and 300-500mm axial length fractures with fracture radius of 5m and 10m is completed by using the axial cutting top technology of matte jet. The key technical parameters of fracture cutting and fracturing process, such as pressure, time and sand amount, are determined. The results of two processes, the implementation of the initial roof caving project and the recovery process in the expanding area of the working face of I010206 were analyzed. The results of four sections of slit in the hole, fracturing curve, fracture morphology of the hole and fracturing water showed that the whole roof seam network of the expanding surface was open. The analysis results showed the effectiveness and reliability of the implementation process of the technology project. The test and analysis of the effect of stoping process after surface expansion show that the caving situation of the first roof caving with the axial cutting of the frosted jet basically achieves the effect of the traditional blasting at the same time, the effect of the roof on the coal wall of the working face is significantly improved, the stress drop of 2.9MPa occurs in the coal body during the engineering implementation process, and the stress concentration degree of the coal body is significantly improved during the surface expansion stoping. The stress of coal body does not form stress concentration, which plays a good pressure relief effect. Through engineering practice, a new treatment mode of hard roof with wide ditch is formed.