The present disclosure relates to a signal acquisition device, a signal acquisition method and a wearable apparatus. A preamplifier circuit in the signal acquisition device amplifies an obtained sEMG signal to produce an amplified sEMG signal. A baseline drift suppression circuit in the signal acquisition device extracts a first low-frequency component from the amplified sEMG signal and performs subtraction processing between the amplified sEMG signal and the first low-frequency component to obtain a difference signal. A filter circuit in the signal acquisition device filters the difference signal to obtain a target acquisition signal. With introduction of baseline drift suppression in the signal acquisition circuit, the baseline drift caused by a low-frequency component in a sEMG signal is eliminated, and the stability of a target acquisition signal is enhanced.
