To apply for a visa to the United States, should I buy a plane ticket or apply for a visa first?

You need to book a plane ticket from China to the United States according to your itinerary. It is generally recommended to book a round-trip air ticket. Note: This is a reservation, and tickets are not issued. After booking, please ask the travel agency or airline to provide the ticket reservation form. Please provide this air ticket reservation form when applying for an American visa. If the visa is passed, the ticket can be officially issued.