Tonghai County, under the jurisdiction of Yuxi City, Yunnan Province, is located on the lake plain beside Qilu Lake in the south of the central border of Yunnan Province. It borders Huaning County in the east, Eshan Yi Autonomous County and Hongta District in the west, Shiping County and Jianshui County in Honghe Prefecture in the south, and Jiangchuan District in the north, with a total area of 721 square kilometers. It has jurisdiction over 2 streets, 4 towns and 3 townships.

The special geographical and natural conditions of Tonghai County achieved the reputation of "famous State of rites and music", "beautiful Southern Yunnan" and "crown Southern Prefecture". In the Ming and Qing Dynasties, there were more than 230 scholars and 44 scholars, 4 of whom were elected to the Imperial Academy. It has successively won the honorary title of provincial Historical and Cultural City, National Advanced County of Cultural relics, National Advanced County of Culture, Chinese Couplets Cultural County, Hometown of Chinese Poetry, National Historical and Cultural City and so on.

By the end of 2021, the resident population of Tonghai County is 288,600. In 2021, Tonghai County achieved a gross regional product (GDP) of 19,43295 million yuan. The added value of the primary industry was 2,98343 million yuan, that of the secondary industry was 5,02371 million yuan, that of the tertiary industry was 11,42581 million yuan, and the proportion of the tertiary industry was 15.4:25.9 ∶58.8.