Shimian County is located in the east of Hengduan Mountains on the Qinghai-Tibet Plateau, the middle reaches of Dadu River and the southwest of Ya 'an City. The geographical coordinates of Shimian County are 101°55 '-102°34' east longitude and 28°51 '-29°32' north latitude. The total area of Shimian County is 2678 square kilometers. Summer rains are concentrated, night rains are frequent, storms are rare, and there is no autumn rain. Currently, it has jurisdiction over 3 towns and 8 townships (including 5 minority townships) and 1 street. 51 villages, 10 residents' committees, 284 villagers' groups, 64 residents' groups, the county government in Mian Cheng Street. According to the seventh census, the permanent population of Shimian County was 114,116 as of midnight on November 1, 2020.

In the thirteenth year of Daoguang of Qing Dynasty (1833), the land was changed back to the flow, and the fourteen blocks were set up in Shunhe Township. In the late Qing Dynasty, the "preparatory Constitution" made Shunhe an autonomous township, and the north bank was all owned by Shunhe Township. In the three years of the Republic of China (1914), Qingxi County for Hanyuan County, Hanyuan County is a southern district Shunhe Township. On May 9, 1952, the Administration Council approved the formal establishment of Shimian County. In January 1956, Wanggangping was transferred from Hanyuan County to Shimian County, and the county boundary was fixed. In 2013, it was rated as the province's "agriculture, rural" work advanced county, "Sichuan biogas County." Shimian County specialty chestnut, walnut, citrus and gastrodia elata, fritillaria, rhubarb, cordyceps and other precious medicinal materials. There are giant panda, red panda, musk deer, leopard, bear and other rare animals under state protection, and it has the reputation of "the hometown of giant panda".

Shimian County famous figures have Lai Ning, Lai Gongzhong and so on. In September 2016, Shimian County was included in the national key ecological function zone. In July 2020, it was reconfirmed as "2019 National Sanitary Township (county)" by the National Patriotic Health Campaign Committee.
In 2020, the GDP of Shimian County reached 10.238 billion yuan, an increase of 5% and 1.2 percentage points higher than that of the whole province.