A county was established in the early Han Dynasty and was named Xuyan. With the changes of history, it was successively changed to Yanchuan County, Yanzhou, Huamachiying, Huamachi Sub-prefecture, etc. In 1913, Yanchi County was established. The county currently governs 4 towns, 4 townships, 98 village committees, 675 villager groups, 1 street office, and 9 communities, with a total population of 165,000, including 132,000 agricultural people, accounting for the county's total population 79.5% of the population; there are 4,044 ethnic minorities, mainly Hui, accounting for 2.4% of the county's total population.

As a national Tan sheep production area and a key county for animal husbandry production in Ningxia, the annual breeding volume of Tan sheep is more than 1 million, and Tan sheep products such as Ermao skin and Tan mutton are well-known at home and abroad. In 2005, the "Yanchi Tan Sheep" certificate of origin trademark was successfully registered. In 2007, the number of Tan sheep raised in the county reached 1.378 million. The livestock industry, mainly Tan sheep, has become a pillar industry of local agriculture and rural economy.