split是分开，split hairs可不是分开头发的意思，而是指生活中某些人“在鸡毛蒜皮的事上争论不休”，即钻牛角尖、吹毛求疵。

【例句】
You really don't need to split hairs on this issue.
对于这件事，你实在不必钻牛角尖。

Let's not split hairs over words, let's look at the facts.
我们不要吹毛求疵了，还是看看实际情况吧。