Abstract: The present disclosure provides a heart-rhythm signal-processing method, including the following steps: obtain PPG signals; perform a labeling operation to determine whether inappropriate signal data exist in the PPG signals and label the inappropriate signal data; perform a first separation operation to remove the inappropriate signal data from the PPG signals and separate the PPG signals into continuous signal segments; find peak positions of the continuous signal segments; perform a second separation operation to separate the continuous signal segments into sub-signal segments according to the number of peaks required for interpretation; perform a feature-extraction operation to obtain feature values respectively corresponding to each of the sub-signal segments, wherein the feature values are relative to peak-to-peak intervals (PPI) of the sub-signal segments; perform a judgement operation to judge the feature values using a judgement model and determine whether the heart rhythm of the subject is belong to