Abstract: For actual demand of nearly horizontal hole drilling of coal seam methane, the paper proposed a scheme of auto-orientation of jet stream of hydraulic correction combining with hydraulic correction technology and designed a correction system based on the scheme. The correction system takes a single-chip microcomputer as control core, uses a pressure sensor to monitor changes of drilling hydraulic pressure so as to start or end hydraulic correction process, and adopts an angle sensor and a digital compass to detect azimuth and inclination of horizontal hole. Then the single-chip microcomputer determines jet direction in accordance with values of the inclination and azimuth and their correlations. The debugging indoor demonstrated feasibility of the scheme.