A density-based data clustering method, comprising a parameter-setting step, a first retrieving step, a first determination step, a second determination step, a second retrieving step, a third determination step and first and second termination determination steps. The parameter-setting step sets parameters. The first retrieving step retrieves one data point and defines neighboring points. The first determination step determines whether the number of the data points exceeds the minimum threshold value. The second determination step arranges a plurality of first border symbols. The second retrieving step retrieves one seed data point from the seed list, arranges a plurality of second border symbols and defines seed neighboring points. The third determination step determines whether a data point density of searching ranges of the seed neighboring points is the same. The first termination determination step determines whether the clustering is finished. The second termination determination step determines whether to finish the method steps.