Sanmenxia lies on the Zhengzhou–Xi'an high-speed railway corridor, making it easy to reach from either city. From Zhengzhou the journey takes about an hour; from Xi'an about ninety minutes. The high-speed station (Sanmenxia South) is south of the city; the older Sanmenxia station on the Longhai line is more central. Both stations are served by taxis.
There is no civilian airport at Sanmenxia. The nearest options are Luoyang (150 km east) or Xi'an's Xianyang Airport (240 km west). Sanmenxia works well as a stop on a Zhengzhou–Xi'an journey — you can break the journey here for a day or overnight and take the next train onward.