Minecraft Thorns Enchantment?

Is it worth the enchantment multiple times to give my armor set, or adds the damage / the chance of damage with several enchanted armor parts?

So. First, it depends on what level you want to do the enchantment on your armor. You can drop in on Minecraft Wiki and see how much damage that does. However, keep in mind that the armor with thorns breaks faster, so maybe you should get protection and / or mending (repair).