Method and device for dynamic measurement of well deflection and tool face angle under small inclination angle condition

The invention discloses a method and device for dynamic measurement of the well deflection and the tool face angle under the small inclination angle condition. By conducting phase-sensitive detecting, smoothing and amplitude limiting on an accelerometer signal measured in a spud-in state, side affects caused by disturbance of underground strong vibration signals and impact can be effectively reduced. The device mainly comprises a signal acquiring unit used for acquiring the acceleration signal and conducting phase-sensitive detecting and smoothing on the acceleration signal, and a digital signal processing unit used for processing the signal input by the signal acquiring unit and outputting parameters of the well deflection and the tool face angle according to the acceleration signal.