A data storage device may include: a nonvolatile memory configured to store L2P (Logical to Physical) map data and user data; and a controller configured to determine whether read commands which are sequentially transferred from a host device correspond to a backward sequential read, increase a backward sequential read count when the read commands are backward sequential read, set a pre-read start logical block address (LBA) and a length according to a preset condition, when the backward sequential read count is equal to or greater than a reference value, and load an L2P map of the corresponding LBA and user data corresponding to the L2P map from the nonvolatile memory in advance.