A steering control device configured to control a steering system with a structure in which a power transmission path between a steering unit that is connected to a steering wheel and a turning unit that turns turning wheels is cut off, the steering control device comprising control circuitry configured to perform synchronization control for adjusting a steering-side rotation angle that is a rotation angle convertible to a steering angle of the steering wheel, by operating a steering-side motor such that a positional relationship between the steering-side rotation angle and a turning-side rotation angle that is a rotation angle convertible to a turning angle of the turning wheels is a predetermined correspondence relationship, the steering unit including the steering-side motor configured to rotate the steering wheel, wherein the synchronization control includes: a target synchronization angle calculating process of calculating a target synchronization angle that is the steering-side rotation angle satisfying the predetermined correspondence relationship with respect to the turning-side rotation angle; characterized in that, the synchronisation control further includes: a target relay angle calculating process of calculating a target relay angle that is located closer to a first side in a circumferential direction than a first-side angle is, the first-side angle being one of the steering-side rotation angle and the target synchronization angle and being located closer to the first side than another of the steering-side rotation angle and the target synchronization angle is; and a motor driving process of operating the steering-side motor such that the steering-side rotation angle reaches the target synchronization angle after operating the steering-side motor such that the steering-side rotation angle reaches the target relay angle. control circuitry configured to perform synchronization control for adjusting a steering-side rotation angle that is a rotation angle convertible to a steering angle of the steering wheel, by operating a steering-side motor such that a positional relationship between the steering-side rotation angle and a turning-side rotation angle that is a rotation angle convertible to a turning angle of the turning wheels is a predetermined correspondence relationship, the steering unit including the steering-side motor configured to rotate the steering wheel, wherein the synchronization control includes: a target synchronization angle calculating process of calculating a target synchronization angle that is the steering-side rotation angle satisfying the predetermined correspondence relationship with respect to the turning-side rotation angle; characterized in that, the synchronisation control further includes: a target relay angle calculating process of calculating a target relay angle that is located closer to a first side in a circumferential direction than a first-side angle is, the first-side angle being one of the steering-side rotation angle and the target synchronization angle and being located closer to the first side than another of the steering-side rotation angle and the target synchronization angle is; and a motor driving process of operating the steering-side motor such that the steering-side rotation angle reaches the target synchronization angle after operating the steering-side motor such that the steering-side rotation angle reaches the target relay angle. a target relay angle calculating process of calculating a target relay angle that is located closer to a first side in a circumferential direction than a first-side angle is, the first-side angle being one of the steering-side rotation angle and the target synchronization angle and being located closer to the first side than another of the steering-side rotation angle and the target synchronization angle is; and a motor driving process of operating the steering-side motor such that the steering-side rotation angle reaches the target synchronization angle after operating the steering-side motor such that the steering-side rotation angle reaches the target relay angle.