A position-encoding device includes a sensing device, a filtering device, a calibrating device and a compensating device. The sensing device senses the motion of a moving device to generate first and second signals. The filtering device filters the first and second signals to generate first and second filtering signal. The calibrating device captures the first and second filtering signals to obtain time and phase information of the first and second filtering signals, performs gain and offset calibration on the first and second filtering signals, and performs a phase calibration on the first and second filtering signals through first, second feedback signals and the time and phase information of the first and second filtering signals to generate first and second calibrating signals. The compensating device compensates for the first and second calibrating signals according to a lookup table, so as to generate first and second position encoding signals.