Tianzhen County, subordinate to Datong City of Shanxi Province, is located in the northeast end of Datong City, at the junction of Shanxi, Hebei and Mongolia provinces (regions), Huaian County of Hebei Province in the east, Yanggao County of Shanxi Province in the west, Yangyuan County of Hebei Province in the south, Xinghe County of Inner Mongolia in the north, known as "the crow of the rooster and the sound of the three provinces".

With a total area of 1,718 square kilometers, Tianzhen County has jurisdiction over 5 towns (Yuquan, Guqianpu, Mixingguan, Lu Jiawan and Xinpingpu), 6 townships (Shilipu, Jiajiatun, Zhaojiagou, Majiasao, Nangua Ya and Zhangxihe), 172 administrative villages and 16 communities. It is a key county in the national poverty alleviation and development work, and is listed as an area of extreme poverty in the Yanshan-Taihang Mountains. According to the seventh census, as of midnight on November 1, 2020, the permanent population of Tianzhen county was 160,691.

Tianzhen County has a long history and has been inhabited by human beings since the Neolithic Age. In the Warring States Period, it was Yanling Town of the State of Zhao; in the Western Han Dynasty, Yanling County was established; in the Tang Dynasty, Tiancheng Army was established; in the Liao Dynasty, it was Tiancheng County; in the Jin Dynasty, it was Tianchengbao; in the Ming Dynasty, it was reformed into Tianchengwei and Zhenluwei. Qing Shunzhi three years (1646) synthetic Tianzhen Wei, Yongzheng three years (1725) called Tianzhen County. In 2020, the GDP of Tianzhen County reached 4.069 billion yuan, an increase of 3.7% over the previous year.

On February 27, 2020, with the approval of Shanxi Provincial government, Tianzhen County was removed from the impoverished county.