According to one embodiment, a magnetic disk device includes a disk, a head including a write head and a first read head and a second read head, and a controller that disposes the first read head at a first radial position of a first track of the disk in a radial direction to read the first track, changes a main read head which serves as a reference for positioning during a read process from the first read head to the second read head when read retrying the first track, disposes the second read head as the main read head at a second radial position different from the first radial position of the first track in the radial direction to read the first track, and changes an internal setting corresponding to the main read head to read the first track.