Abstract: In recent years, directional drilling technology has been greatly popularized and applied in the field of coal mine safety and geological exploration due to its advantages such as deep drilling depth, high drilling accuracy and controllable trajectory. However, the technology still has large water consumption and high cost of directional drilling. By analyzing the size and distribution of drill cuttings particles, a directional drilling water cycle technology for coal mine is studied, and an industrial test is carried out in Sihe Coal Mine. Tests show that the set of technology realizes the cycling use of water in horizontal directional drilling, greatly reduces the directional drilling cost.