VERB的問題

Grammatically speaking, your sentence is correct.

The sentence has only one finite verb, which is "help". It becomes "have helped" in the present perfect tense with plural subject.

"discourage" is a non-finite verb, a bare infinitive following the main verb "help" (have helped).

"discourage" is a transitive verb which can take on a noun/noun phrase or gerund as its object.
e.g. discourage illegal immigration
discourage smoking in public area

"discourage somebody from doing something" is also a common expression.

Your sentence isn't grammatical.

DON'T USE PRESENT PERFECT TENSE IN THIS SITUATION!

NO PLURAL FORM!

You should say:

Graphic warning labels on cigarette PACKAGE HELPS discourage smoking.

Be aware that perfect tenses can't be applied to this case, present tenses should be used.

No matter in the past, now and future, we always use
health warning on cigarette package to persuade smokers to give up their
smoking habits. It is common truth and accepted by people around the world.

If perfect tense is used, it only tells people warning statements could help people stop smoking from an unspecified time point (10 or 20 years before) till now but can't tell us this claim would apply in the future.

Better to write us:

The disgusting pictures and health warning on cigarette boxes discourage people from somking/ abstaining their smoking habits.

Then, you don't need to put 2 finite verbs on a sentence.