A data reading method for a rewritable non-volatile memory module is provided, wherein the rewritable non-volatile memory module has a plurality of physical pages. The data reading method includes grouping the physical pages into a plurality of physical page groups and configuring a corresponding threshold voltage set for each of the physical page groups. The data reading method also includes respectively reading data from the physical pages of the physical page groups by using the corresponding threshold voltage sets. The data reading method further includes when data read from one of the physical pages of one of the physical page groups cannot be corrected by using an error checking and correcting (ECC) circuit, updating the threshold voltage set corresponding to the physical page group.