Huailai County, subordinate to Zhangjiakou City, Hebei Province, is located in the northwest of Hebei Province, with its center at about 115 ° east longitude and 40 ° north latitude. With a total area of 1801 square kilometers, it is located in the semi-arid area of the middle temperate zone and belongs to the temperate continental monsoon climate. As of October 2021, Huailai County has jurisdiction over 11 towns and 6 townships, and the county people's government is stationed in Shacheng Town. As of March 2022, Huailai County has a total population of 367000.

In ancient times, Shun set up twelve prefectures and Huailai belonged to Jizhou. In the 32nd year of Kangxi's reign in the Qing Dynasty (1693), it was changed to Huailai County. Huailai County has Jingbao, Fengsha, Daqin and Shawei railways passing through it. The total length of the railway is more than 160 kilometers and there are 17 stations, making it one of the counties with the largest number of stations at the county level in China. The main scenic spots are Jimingyi Ancient City, Yan Great Wall, Ming Great Wall, etc.

In 2021, Huailai County will achieve a GDP of 14.21 billion yuan, an increase of 6%.