How can I check which projectile hit the charactor?

why don’t you go for has component tag node? it’s extremely easy and will be helpful here

I my using OnComponentHit node to check if the character is hit by the projectile. However, I have multiple projectile(different blueprint class) that can be launched, and I would like to know the character is hit by which one of them. Thanks.

I think you can use cast nodes to check for certain projectiles.
You can read more here:

add an tag at projectile component and in component has tag type the same tag name , use branch to check if it’s been hit by that one or other.

i’ll check it out, thanks!