A storage unit management method for managing a plurality of physical units in a rewritable non-volatile memory module is provided, wherein the physical units are at least grouped into a data area and a spare area. The method includes configuring a plurality of logical units for mapping to the physical units belonging to the data area, and determining whether the rewritable non-volatile memory module contains cold data. The method further includes performing a first wear-leveling procedure on the physical units if it is determined that the rewritable non-volatile memory module does not contain any cold data, and performing a second wear-leveling procedure on the physical units if it is determined that the rewritable non-volatile memory module contains the cold data.