A data storage device includes a nonvolatile memory device including a first page group coupled to a first word line and a second page group coupled to a second word line, which is subsequent to the first word line in order of a write operation; and a controller suitable for, after an abnormal power-off during a write operation to the first page group, copying a first data stored in a weak page of the first page group to a stable page of the second page group when a first error correction operation to data stored in the first page group is a success.