Abstract: 　　Experimental study is conducted on automatic well inclination control, by using the automatic vertical drilling tool principle prototype. Through analyzing the principle of inclination measurement based on gravity accelerometer and combining the work principle of prototype inclination mechanism, the method by which each inclination mechanism’s working area is rightly divided is proposed, as well as the well inclination real-tine control system is developed by using the method and virtual instruments technique. By the system, the well inclination precision has reached no less than 0.15° currently.