Ejin Banner is located in the westernmost part of the Inner Mongolia Autonomous Region, connected to Alxa Right Banner in the southeast, adjacent to Gansu Province in the west and southwest, and bordering Mongolia in the north. The border is 507 kilometers long. The total area of the banner is 114,600 square kilometers, accounting for 42% of the total area of the league. It has jurisdiction over 3 towns, 6 Sumu, 2 street offices, 21 Gacha and 7 communities. Mongolian, Han, Hui and other 12 ethnic groups live in Mongolia, ethnic Mongolians accounted for 16.1% of the population. Ejin Banner is the flag with the largest area and the smallest population in Inner Mongolia Autonomous Region. According to the seventh census, as of midnight on November 1, 2020, the permanent population of Ejin Banner was 35,756. Dongfeng Space City (Jiuquan Satellite Launch Center) is located in Ejin Banner, is the birthplace of Chinese missiles, satellites, manned spacecraft, known as "China's first space port".

The terrain of Ejin Banner gradually slopes from southwest to northeast. It is high on all sides and flat in the middle. The altitude is between 898 meters and 1598 meters. The landform is mainly composed of Gobi, low mountains, deserts, rivers, lakes and oases.

Heihe River, originating from the northern foot of Qilian Mountain in Qinghai Province (called Weak Water in ancient times, Heihe in the upper and middle reaches, and Ejin River in the Qi area), is the mother river of Ejin. From south to north, it enters the Qi through Zhangye, Gaotai, Jinta and other cities and counties in Gansu Province, and reaches Bayan Baogede (Langxin Mountain) into two rivers in the east and west. In the north, it is divided into 19 tributaries, and finally flows into the East and west Juyan Sea. Forming Ejin Oasis of 31,600 square kilometers.

In 2020, the GDP of the whole Banner reached 3.81 billion yuan, up 0.7 percent year on year.

In December 2019, Ejin Banner was awarded the seventh batch of National Demonstration Zones for Ethnic unity and Progress. In October 2020, it was rated as the national model city (county) of double support.