guys i used to play soul hunters on my ipad, but today i bought a iphone but i can t recover my acc to my new equipment (i used facebook account) is there someting i need to do?

It shouldn't be a problem as long as you're playing the same platform (iOS)
What kind of iPhone you bought?

iphone 6... and i have a ipad mini 2... both use ioas 10 i think

Is it both iOS 10.2? Or I just forgot Facebook binding getting messy these days?

It shouldn't matter if they are the exact version, just the same OS. I have 2 phones with different android versions and with both I can play with my FB account.

Better write them on FB (chat) or the email of support.