Sanjiang Dong Autonomous County, under the jurisdiction of Liuzhou City, Guangxi Zhuang Autonomous Region, is located in the north of Guangxi Zhuang Autonomous Region. It is located at 108°53 '~ 109°52' east longitude and 25°22 '~ 26°2' north latitude, with a total area of 2,454 square kilometers. It is connected to Longsheng Autonomous County and Rong 'an County in the east, Rongshui County and Congjiang County in Guizhou Province in the west. It is close to Tongdao County of Hunan Province and Liping County of Guizhou Province in the north, and to Rongan County and Rongshui County in the south. Guyi Town is 203 kilometers away from Liuzhou City and 167 kilometers away from Guilin City. In 2017, it has jurisdiction over 6 towns and 9 townships. According to the seventh census, as of midnight on November 1, 2020, the permanent population of Sanjiang Dong Autonomous County was 321,538.

Sanjiang Dong Autonomous County is the intersection of Hunan, Guangxi and Guizhou provinces (districts). It belongs to the subtropical Nanling humid climate zone and mountain valley climate zone. Famous scenic spots include: Shimen Chong Natural ecological scenic spot, Chengyang Bazhai Scenic spot, Danzhou Scenic spot, etc. On Nov 14, 2019, Sanjiang Dong Autonomous County was named the third batch of national demonstration counties for ecological civilization construction by the Ministry of Ecology and Environment. China's top 100 clean water counties and cities in 2020. On November 20, 2020, the People's Government of Guangxi Zhuang Autonomous Region approved its withdrawal from the poverty-stricken county list.

In 2020, the GDP of Sanjiang Dong Autonomous County reached 7.844 billion yuan, up 5.9 percent year on year.