Is it easy to buy train tickets from Xining to Lhasa in mid-May?

Don’t know how to take a plane, the train takes a long time and is uncomfortable.
This is unclear, I am driving a self-drive tour.
Xining to Lhasa Z323 has a relatively higher safety factor. Many people will experience altitude sickness symptoms such as headache and fatigue upon arriving in Lhasa. The train journey is quite lengthy, during which one can relax and adjust to the high altitude gradually (oxygen is released on the train, and altitude medicine is sold). The Qinghai-Tibet Railway, the world’s highest railway line, is a must-experience journey in one’s life. Every year, foreign tourists come to experience it by name, so remember to book tickets early! If it were not for the yq, it would be very difficult to buy tickets! The memories of the outside and inside of the window are for a lifetime. Outside, you will pass by lakes, rivers, grasslands, hills, and high mountains, where you will encounter antelopes, yaks, handsome horses, and even deer. A snapshot at any moment is a large scene. Inside, it will also not disappoint you. The long journey will take you back to the era when communication was slow and letters were far away. You are sure to meet companions with similar interests, each taking out their own snacks and good wine, and exchanging each other’s stories. About the train ticket: Xining to Lhasa Z323 is very difficult to get a ticket, choose an oxygen train! The reason for entering the Tibetan Plateau is to see the scenery along the way, pass by Qinghai Lake, cross the Tanggula Mountains, and enter the可可西里无人区. However, the signal on the train is often not good, and the charging ports are scarce. About the preparation of medicine for entering the Tibetan Plateau: cold medicine, gastrointestinal medicine, glucose powder (it is very useful to dissolve it in water), headache medicine, motion sickness medicine, vitamin C effervescent tablets, erythromycin ointment (apply it to the nose before going to bed, which is not easy to dry), menthol (the wonder of motion sickness), personal care items: wash bag (it is very convenient to hang the wash hook next to the train), face towel, towel, toothpaste, toothbrush, facial cleanser, moisturizer, mask, wet wipes, shampoo, conditioner, body milk, hand cream, lip balm (apply thickly before going to bed), sun protection products: sunscreen, sun protection clothing, sun protection pants, sun hat, ice sleeves, sun protection mask, sunglasses, umbrella (the rain in Lhasa will pour down suddenly), cosmetics: (carry only the necessary items for a simple makeup), clothing: light down jacket (the temperature difference between day and night is large), thickened sweater, long-sleeved cardigan, pajamas, shawl (for sun protection during the day and warmth at night), hat, slippers, socks, shoes, disposable underwear (do not forget), short-sleeve shirts on the train, other items: contact lenses and lens solution, tissues, wet wipes, power bank (charging ports on the train are scarce and not very useful), charger, small humidifier, thermal cup, garbage bag (do not forget), selfie stick, earphones, a small amount of cash (you will know that many places in Lhasa need cash), snacks and fruits (prepare according to your needs), the three essential sets for going out: ID card, mask, mobile phone! Stop aerobic exercise one week before entering the Tibetan Plateau, do not enter if you have a cold!!! At an altitude of about 4000 meters, there will be obvious headaches, shortness of breath, and slow walking, which will be several times slower than usual. In addition, when crossing the mountain passes, the altitude is higher, the wind is strong, and the headache will be more severe! The whole journey did not need to breathe oxygen, but it was still very difficult to persevere. Maintain sufficient sleep, drink plenty of hot water, do not run, jump, or get excited! The first night can stay in an oxygen hotel, so there is no need to worry about altitude sickness too much!
How many trains are there from Xining to Lhasa, and it’s still safer to buy tickets in advance.
Seeing whether or not the holiday is a good time to buy usually depends on the availability.