Abstract: Grouting is the important measure of reinforcing soft rock and plugging water-containing strata, directional drilling grouting technology China's coal mine has been used for nearly 40 years in coal mines in China. Firstly, two main forms of grouting by directional drilling technology are introduced in Chinese coal mines in the paper, namely s-shaped small displacement directional borehole used in pre-grouting for vertical shaft and L-shaped extended-reach directional borehole used in grouting transformation for large area formation(it includes the conventional horizontal directional drilling grouting from ground surface, the horizontal directional drilling grouting from ground surface in which part of existing geological borehole is used, the horizontal directional drilling grouting in underground roadways), the depth of pre-grouting for vertical shaft by s-shaped directional borehole and the horizontal displacement length of ground directional borehole for grouting deep strata have all exceeded 1000m; secondly, the author indicates that directional drilling grouting technology is facing a lot of questions, such as grouting theory, process and equipment, inspection and evaluation of the grouting effect, and so on, with the continuous development of coal mining to the deep extension and the scale of a single face continues to increase; thirdly, the author indicates that researchers should strengthen the research on simulation test system for grouting rock under flowing water conditions and grouting simulation test, detection method on grouting effect of deep strata and spread regularity of grout(especially, grouting by horizontal drilling method), detection on grouting effect, find out the main influencing factors of grout diffusion in deep strata, so the law of grout diffusion can be revealed. This paper can provide reference for the program development of grouting deep strata in coal mine, and also points out the research directions of directional grouting technology.