✔ 最佳答案
Harry and Hermione don't actually kiss in Deathly Hallows--that's a hallucination generated by Voldemort's Locket Horcrux, intended to provoke Ron into deserting them again (or killing Harry).
But instead, at Harry's urging, Ron stabs the locket with Gryffindor's sword (which they had just retrieved), destroying the fragment of Voldemort's soul which the locket contained. At this point, the power that the locket had exerted over the three friends is broken, and they reconcile with each other.
參考: Read the book as soon as it came out.