I have a train ticket from Lhasa to Delingha, and now I am planning to buy a train ticket from Delingha to Lanzhou, prompting a conflict in the itinerary

You must have bought the same train. You cannot buy the same train twice on the same day. It is recommended that you buy another train<a target="_blank" class="gs_a_poi" href="http://you.ctrip.com/place/delingha891.html#ctm_ref=gs_290102_1756124_891_l" data-classtype="1" data-id="674" data-type="4">Delingha</a><p>arrive</p><a target="_blank" class="gs_a_poi" href="http://you.ctrip.com/place/lanzhou231.html#ctm_ref=gs_290102_1756124_231_l" data-classtype="1" data-id="148" data-type="4">Lanzhou</a>, that's it, I hope it can help you, hope to adopt it!