As far as villains go, the Harry Potter franchise's Dark wizard Lord Voldemort ranks high on the list of most vile. Not only did he commit violent mass murder and promote prejudice and blood purity that extended beyond the Wizarding World, but Voldemort spent years targeting a little boy who threatened his quest for immortality. But why did Voldemort want to kill Harry? While it may seem ridiculous for such a powerful wizard to feel so threatened by a mere child, Voldemort's first attempt to eliminate Harry Potter bounced back on him and put him out of commission for twelve years. But that was only part of the reason Voldemort was so driven to wipe out the one person who might actually be able to stop him from achieving his hideous goals. The real question boils down to why Voldemort came to Godric's Hollow to kill Harry Potter in the first place, and the answer is as simple as it is complicated: a prophecy.
Source：https://www.cbr.com/why-voldemort-wanted-to-kill-harry/
