Abstract: Based on the introduction on development of the horizontal directional drilling technology at home and abroad underground coal mine,the paper analyze d and summarized the major features,application scope and technique method of the directional drilling rig,the measuring system with the drilling,matched drilling tools and the directional drilling technique.In combination with the site applications,the paper fully stated the high drilling efficiency in the operation of the horizontal direction al drilling technology in underground coal mine,high control accuracy of the borehole tracing(the horizontal displacement 0.5% less than the borehole depth and the top and low displacement 0.1% less than the borehole depth) and the features of the high construction operation.Based on the technical development and site application,t he paper had prospects on the technology and equipment of the horizontal directional drilling in underground mine.