Abstract: In order to realize high efficiency and low cost control of coal seam gas drainage, this paper proposes the technical system for gas drainage by means of directional multi-branch drilling. The fixed-point and fixed-size drilling sealing technology with pressure named "double sealing and one grouting" is improved to determinate coal seam gas pressure, and the airtight sampling device for fixed-point coal in the deep drilling is developed.In addition, the intensified techniques of gas drainage are optimized according to directional multi-branch drilling, then the technical system for gas drainage by means of directional multi-branch drilling is formed. The field engineering test results show that, the directional multi-branch drilling is successfully constructed with a depth of more than 630 m in Yongxia mining area, coal sample in the max depth of 632 m is fetched hermetically by the airtight sampling device, the structure of hermetically sampling device is reasonable; the results of the coal seam gas content, the initial emission rate and the drilling cutting agrees well with each other in position, the reliability of the test results meets the requirements; the gas emission rate is positively correlated with the tunneling speed, and the position of maximum gas emission rate is consistent with that of maximum gas content and regional verification indexes, which proves the reliability of the proposed technical system.