Flying from China to the USA takes as little as 12 hours. That's pretty quick since China is over 7,000 miles away from the USA.
Of course if you go further into the United States on the flight it could take up to 18 hours but still less than a day is a quick flight from China to the USA.
Taking a ship would take 25 to 40 days to reach the USA from China so if you're planning on going to the USA from China or from the USA to China then the Plane is the way to go if you want to get there quickly.