A data recovery device including an analog to digital converter (ADC), a filtering-equalizing unit, a zero crossing detector, a data phase locked loop, a data mapping unit and an estimation unit is provided. The ADC converts a radio frequency signal to a plurality of sampling data points. The sampling data points are converted to a plurality of retiming data points and a clock signal by the filtering-equalizing unit, the zero crossing detector and the data phase locked loop. The data mapping unit selects a plurality of maximum data points and minimum data points from the returning data points, and determines whether to map the maximum data points and the minimum data points to other levels for partially reconstructing the retiming data points. The estimation unit recovers the reconstructed retiming data points to a modulation signal.