What is the fastest express train from Xi 'an to Jingbian?

Shunfeng. According to Baidu Encyclopedia, SF Express is the fastest express service platform in China, so SF Express is the fastest from Xi 'an to Jingbian. Established in 1993 and headquartered in Shenzhen, SF Express Co., Ltd. is a service-oriented enterprise mainly engaged in domestic and international express delivery and related businesses.