I would like to visit Xian, Luoyang and Chengdu in this order

Hi, you can take the route of Xian, Luoyang and Chengdu. It is convenient to travel from Xian to Luoyang by high speed train and the ride only takes around 1.5 hours. From Luoyang to Chengdu, you can take an overnight train and the journey takes about 18 hours. Or you may transfer from Luoyang to Zhengzhou first, and then take flight to Chengdu.