這不是雞毛蒜皮的事。

This isn't a trivial matter.

Source: Tatoeba

Sentence Composition

=1 這不 zhèbu (coll.) As a matter of fact, ... (used to introduce evidence for what one has just asserted)
=1 這不 zhèbù connects two clauses, emphasising how the following clause substantiates the preceding clause
=2 是 shì
  1. to be (followed by substantives only)
  2. correct; right; true
  3. (respectful acknowledgement of a command) very well
  4. (adverb for emphatic assertion)
=2 是 shì variant of 是 shì
3 雞毛蒜皮 jīmáosuànpí
  1. lit. chicken feathers and garlic skins (idiom)
  2. fig. trivial (matter)
=4 的 de
  1. of; ~'s (possessive particle)
  2. (used after an attribute when it modifies a noun)
  3. (used at the end of a declarative sentence for emphasis)
  4. (used after a noun, verb or adjective to form a nominal expression, as in 皮革的 pígéde "one made of leather" or 跑堂兒的 pǎotángrde "a waiter (literally, one who runs back and forth in a restaurant)" or 新的 xīnde "new one")
  5. also pr. dì or di in poetry and songs
=4 的 dī a taxi; a cab (abbr. for 的士 dīshì)
=4 的 dí really and truly
=4 的 dì (bound form) bull's-eye; target
=5 事 shì
  1. matter
  2. thing
  3. item
  4. work
  5. affair

classifiers: 件, 樁, 回
=5 事 zì
  1. alternative form of 倳 (zì, “to establish”)
  2. alternative form of 剚 (zì, “to stab”)