Sanyuan County, subordinate to Xianyang City of Shanxi Province, is located in the north of Xianyang City, connected with Lintong District, Yanliang District and Fuping County of Weinan City in the east, Gaoling District of Xi 'an City in the south, Jingyang County and Chunhua County in the west, and Tongchuan New District and Yaozhou District in the north, covering an area of 576.9 square kilometers. As of October 2022, Sanyuan County has jurisdiction over 1 subdistrict and 9 towns. In 2021, the registered population of Sanyuan County was 403,711.

In the middle of the Neolithic Age (6000~ 5000 years ago), ancient people in the northern part of Sanyuan County engaged in animal husbandry, fishing and hunting, and farming. Han Hui Emperor four years (191 years ago), to its land in Chiyang County. In the first two years (352) of the Sixteen States period, Emperor Qin set up the Sanyuan Guard Army. Northern Wei Taiping Zhenjun seven years (446 years), strike guard army set Sanyuan County, under the north county. On December 19, 2019, Sanyuan County was listed by the National Development and Reform Commission as a national pilot zone for integrated urban and rural development.

In 2021, the GDP of Sanyuan County reached 23.609 billion yuan, and the per capita disposable income of residents reached 28,505 yuan.