Mianning County, subordinate to Liangshan Yi Autonomous Prefecture of Sichuan Province, is located in the southwest of Sichuan Province, in the north of Liangshan Yi Autonomous Prefecture, bordering Yuexi County and Xide County on the east, Xichang County and Yanyuan County on the south, bordering Muli County and Jiulong County on the north of Yalong River and Yaniu Mountain on the west, and connecting with Shimian County on the north of Bodhgang, covering a total area of 4423 square kilometers. It has jurisdiction over 1 street, 15 towns and 3 townships.

Mianning is located in the Panxi Great Rift Valley. The Anning River and Nanya River originate in the territory. The Yalong River meanders through the southwest and is known as the rice granary beside the Anning River. It is a "national grain production county" and "pig transfer county". It has proved more than 30 kinds of minerals with mining value, of which the rare earth reserves rank second in the country. Mianning is an old revolutionary base. In the 24th year of the Republic of China (1935), the Red Army's Long March passed through Mianning and established the first revolutionary regime after the Red Army entered Sichuan, the Mianning County Revolutionary Committee, and the first revolutionary arm, the Anti-donor Army. Here, Commander Zhu De first proposed the concept of "Long March" in the "Proclamation of the Red Army of Chinese Workers and Peasants", and also here Liu Bocheng and Xiao Yedan "Yi Sea Alliance".

By the end of 2021, Mianning County has a permanent population of 365000. In 2021, Mianning County will achieve a gross regional product (GDP) of 12.76956 billion yuan, including 3.1536 billion yuan of added value of the primary industry (excluding agricultural, forestry, animal husbandry and fishery services), 4.97096 billion yuan of added value of the secondary industry, 4.645 billion yuan of added value of the tertiary industry, and 24.7:38.9:36.4 yuan of industrial structure. The per capita GDP reached 34985 yuan.