Paris did not survive the Trojan War. Although he was alive at the end of Homer's "Iliad," other stories and plays record his death at the end of the war. Soon after he famously shot Achilles' heel, Paris received a mortal wound from the Greek archer Philoctetes.
Paris did not die right away. The wound itself was not fatal, but Philoctetes poisoned the arrow to ensure Paris died. Because there was no antidote for the poison, Paris had to turn to supernatural means to heal his wound.
Paris sought the healing abilities of his first wife Oenone, a naiad or water nymph, to purge the poison from his body. Paris abandoned Oenone years earlier to participate in Trojan politics with his father, the king. After the dying Paris begged for her help, she refused, still hurt by Paris' abandonment and his preference for Helen of Troy.
Paris died soon after Oenone denied his request. She realized what she had done, became distraught and committed suicide. After Paris' death, his brother Deiphobus married Helen. Deiphobus later died by the hand of Menelaus, Helen's original husband whom she left for Paris in the betrayal that started the Trojan War. After the war, Helen returned to Sparta with Menelaus, and they happily remained together.