A fig tree can safely be pruned in winter, which is when it goes into its dormant season. Heavy pruning should only be done only during the tree's first two dormant seasons.
The first pruning should be done early in the dormant season. The second year's pruning should be done in late winter. After the first two heavy prunings, which are typically done during the tree's first two dormant seasons, only light prunings should be needed. These also need to be done during the dormant season. If a heavy pruning is performed after this time, it does not normally damage the tree very much, but it does reduce the amount of figs the tree can produce during the next growing season.