一箭双雕的英文：
[Literal Meaning]
one/arrow/two/hawk
to shoot two hawks with one arrow

[解释]
做一件事达到两个目的。

[Explanation]
to accomplish two different purposes with one action

[例子]
这次去香港即看了多年没见的阿姨，有参加了学术会议，这是一箭双雕。

[Example]
In our visit to Hong Kong this time,it was really buttering both sides of one's bread: we've seen our aunt whom we haven't seen for long and attended the academic conference as well.

[英文等价词]
to kill two birds with one stone
butter both sides of one's bread

He achieved two things at one stroke by doing things this way.
他这么做一箭双雕。

The formation of a foreign legion seemed therefore to be an ideal method of killing these two birds with one stone.
因此,创建外籍军团看来是一种一箭双雕的理想方法。