“当做神话”可以翻译为“treat as a myth” 或者 “regard as a myth” 。
例句：
People tend to treat this ancient legend as a myth. （人们往往把这个古老的传说当做神话。）
Many scholars regard the story as a myth rather than a historical fact.（许多学者把这个故事当做神话，而非历史事实。）