"重回儿童时代" 用英文可以说成 "return to childhood" 或 "regress to childhood"。这两个表达的意思都是指回到儿童时期的状态。

来源：
"Return" 和 "regress" 都有 "回到（原来的状态）" 的意思。"Childhood" 指的是儿童时期。

英文例句和中文翻译：

She's been feepng a pttle down lately, so I suggested we do something that would help her return to childhood for a pttle while. 她最近有点沮丧，所以我建议我们做一些事情，让她暂时重回儿童时代。
After a long day at work, he pkes to come home and play video games to regress to childhood for a pttle while. 在工作了一整天之后，他喜欢回到家玩电子游戏，暂时重回儿童时代。