Zhangxian County, which belongs to Dingxi City, Gansu Province, is known as barrier county because of its important strategic position and is considered as the "barrier to the west" of the Han Dynasty. It was renamed as Wuyang County in the second year of the reign of the Emperor of Heaven in the Tang Dynasty, and Zhangxian County in the Hongwu year of the Ming Dynasty because of "the beautiful water in Zhangshui and the rich land in Baojing".

Zhangxian County is located in the south-central part of Gansu Province, in the transitional zone between the West Qinling Mountains and the Loess Plateau, bordering Wushan County in the east, Zhuoni County in the west, Minxian County in the south, and Longxi County and Weiyuan County in the north, with a total area of 2164.4 square kilometers. According to the seventh census data, as of 0:00 on November 1, 2020, Zhangxian County has a permanent resident population of 167309. It is a key county for national poverty alleviation and development.

Zhangxian County is "the hometown of broad beans in China" and "the hometown of seabuckthorn in China". In August 2008, it was named "China's Green County" by the China Environmental Protection Federation, and in 2005, it was named "China's National Climbing Team Training Base" by the China Mountaineering Association.

On September 25, 2018, it was awarded the honorary title of "2018 Comprehensive Demonstration County of E-commerce in Rural Areas" by the Ministry of Commerce.

In February 2020, after the examination and approval of the leading group of poverty alleviation in Gansu Province, Zhangxian County met the exit conditions of poor counties and was approved to exit. China's top 100 summer leisure counties and cities in 2020.

In 2019, Zhangxian County achieved a gross domestic product of 2.366 billion yuan, an increase of 6.5% over the previous year. Among them, the added value of the primary industry was 580 million yuan, up 6.2%; The added value of the secondary industry was 482 million yuan, up 7.8%; The added value of the tertiary industry was 1.302 billion yuan, up 6.2%. The three industrial structures are 24.59:20.36:55.05, and their contribution rates to economic growth are 26.48%, 25.69% and 51.17% respectively. The per capita GDP is 11865 yuan based on the permanent resident population of 1.994 million.