Autonomous navigation research in the process of drilling has been a very challenging advanced topic and it requires the drill pole must adjust their own space attitude before the directional move. Strapdown inertial navigation has an explicit definition of the space attitude information which will be reflected by the inclination, the azimuth angle and the tool face angle specifically. For the defect in the open mathematical model solver of the spatial attitude information, we derive another mathematical model of the inclination, the magnetic azimuth angle and the tool face angle with the space coordinates transformation, the spatial straight line equation and the dog-leg angle’s definition and give the specific achievable plan by making use of the triple-axis accelerometer and the triple-axis magnetometer. The experimental result indicated that this plan can get the correct spatial attitude within ±0.1º error to the inclination and ±1.5º error to magnetic azimuth angle and the tool face angle. In addition, its cost is very low and the volume is very small, so it is really an ideal choice for the spatial attitude measurement system.