To provide a defrosting control device and a defrosting control method, capable of suppressing a power consumption amount of a refrigeration machine and a peak power at pull-down.

A defrosting control device 4 controls defrosting of a plurality of cooling devices 2 (2a, 2b) for cooling an article with refrigerant supplied from a common refrigeration machine 3. The defrosting control device includes: a season determination unit 4a that determines a current season; and a defrosting setting unit 4b that divides respective cooling device 2 (2a, 2b) into a plurality of groups, and sets a defrosting starting time so as to perform defrosting at different timing in each group when the current season is determined as summer with the season determination unit 4a.