My wife get headache whenever she travel. She notice that when it cover ear from air then there is a no problem. Headache come at one side of head.

Few thoughts. There are lots of ways to travel. They almost all involve sitting in a confined position with your head held in unnatural positions as you are trying to rest. Flying involves pressure changes that can bother the ears, often one side more then the other. Also jet lag, lack of sleep and an unusual schedule is a headache waiting to happen. Get her a neck ring, keep a sane schedule. May c md 4 ear.
Motion Sickness. This sounds like motion sickness. We often use tools such as she has discovered with the covering her ear. She may do well with scopolamine or dramamine (dimenhydrinate) as medications that treat motion sickness.