Do Substitutes have their own HP?

Question

And if they do, how much damage can they take until the substitute dissapears?

Answer 1

Yes, a substitute has hp. The hp of the substitute is equal to 1/4 of the Pokemon's max hp stat. So if a Pokemon has 400 hp, the substitute would have 100 hp. Once the substitute takes 100 hp of damage, then it wears off.
Source

Comments

Thanks!

---

no problem :)

Answer 2

it has 25% of the user's HP.

Using 25% of its maximum HP, the user creates a substitute with 1 HP more than the amount of HP lost by the user.

Source - Bulbapedia