1. By train: take the train from Guyuan Railway Station to Xi 'an, and then transfer to Shenmu City after arriving at Xi 'an. This road needs to stay in Xi for a long time, but you can enjoy the scenery along the way.
2. By plane: fly from Guyuan Airport to Xi 'an, and then transfer to Shenmu after arriving in Xi 'an. This method is faster, but the price is higher.
3. Take a long-distance bus: take a long-distance bus from Guyuan bus station to Xi 'an, and then transfer to Shenmu City after Xi 'an. This way needs to change trains halfway, which takes a long time, but the price is relatively low.
To sum up, Guyuan can choose to go to Shenmu by train, plane and coach. The specific way can be chosen according to your own time, economy and personal preference. If you have enough time and want to enjoy the scenery, you can choose to take the train or coach. If time is tight and the economy allows, you can choose to fly.