After Helian Chang was captured by rival Northern Wei's army in 428, Helian Ding took the throne himself and for several years tried to resist Northern Wei attacks, but by 430 he had lost nearly his entire territory.
After rival Northern Wei's general Daxi Jin (達奚斤) captured the important city of Chang'an in 426, Helian Chang sent Helian Ding south in spring 427 from the capital Tongwan (統萬, in modern Yulin, Shaanxi) to try to capture Chang'an.
However, subsequently, receiving false information that Northern Wei forces had run out of food, he decided to attack Northern Wei forces and was soundly defeated, and he fled to Shanggui (上邽, in modern Tianshui, Gansu).
Helian Ding then entered into an alliance with Emperor Wen of Liu Song against Northern Wei, agreeing to destroy Northern Wei and divide its territory north of the Yellow River—with provinces east of the Taihang Mountains going to Liu Song and west of Taihang going to Xia.
However, neither party actually intended to attack Northern Wei's territory north of the Yellow River first, waiting for the other to act, and Northern Wei's Emperor Taiwu took advantage of this and decided to try to destroy Helian Ding first.
Upon hearing this, Helian Ding personally tried to intercept Qifu Mumo, who was forced to stop at Nan'an (南安, in modern Longxi, Gansu), with his territory having otherwise all fallen to Tuyuhun.
Helian Ding, hearing that Pingliang was under attack, tried to return to Pingliang to relieve it, but on the way he encountered the Northern Wei general Tuxi Bi (吐奚弼), who tricked him by pretending to be a weak force, drawing an attack from him.
Tuxi then defeated Helian Ding, who was then forced to withdraw to Chungu Plains (鶉觚原, in modern Pingliang).
After several days, he forcibly fought his way out of the siege, but his forces mostly collapsed, and he himself was badly injured.
The Northern Wei emperor seized Helian Ding's empress and gave her to his general Doudai Tian (豆代田) as a concubine.
In response, Northern Wei's Emperor Taiwu created Murong Mugui the Prince of Xiqin and gave him rewards, and in spring 432 Murong Mugui delivered Helian Ding to Northern Wei.
When his brothers Helian Shegan (赫連社干) the Duke of Shanggu and Helian Duluogu (赫連度洛孤) the Duke of Guangyang surrendered his capital Pingliang (平涼, in modern Pingliang, Gansu) to Emperor Taiwu of Northern Wei in 430, she was captured.