The invention relates to a dynamic rotation attitude measurement apparatus used for well drilling, and a method thereof. The apparatus comprises a suspension slurry and a compression resistance cylinder, and a power board, a circuit board, a magnesensor, an accelerometer and a gyroscope are arranged in the compression resistance cylinder. The method comprises the following steps: respectively measuring the geomagnetic field component, the earth gravity component and the rotating speed of the whole apparatus through the magnesensor, the accelerometer and the gyroscope, and transforming physical input collected by all sensors into voltage output; removing a harmful acceleration item from output items of the accelerometer according to an installation error coefficient and the rotating speed obtained by the gyroscope in order to realize error compensation; and calculating the dynamic rotation attitude of well drilling according to the geomagnetic field and earth gravity data collected by the accelerometer and the magnesensor. The apparatus and method allow the well drilling attitude in a dynamic rotation state to be measured, and effectively improve the working efficiency of a dynamic well drilling system.