Look at the individual words:

Something came out. Where did it come out from? Under something else.

Ex. I came out from under the bed.

'under the bed' is where I came from.

out from under means to be free from worries and difficulties

脱离危难

嗨 Glen ：）

謝謝呦

有比較清楚：Ｄ

我认为 under 如果你理解为 “处于什么下面”  进而理解为  处于比较低的状态或者正在遭受着什么， out of 有 在....外边，自...离开，这样的话可能会好理解一点，希望对你有帮助！