During Emperor An's reign, those close to him, including the eunuchs Jiang Jing (江京) and Li Run (李閏) and his wet nurse Wang Sheng (王聖), as well as his wife Empress Yan Ji, effectively ran the imperial administration, and used the opportunity to seize power and wealth for themselves.
After several days of battling with the empress dowager's faction, the eunuchs led by Sun prevailed, and the Yan clan was slaughtered.
Sun and Zhang Xian (張賢), another eunuch who had helped put the emperor on the throne, interceded at great personal risk.
He was soon captured, but Emperor Shun, remembering his accomplishments, simply sent him back to his estate without further punishment, but also without listening to his advice on stamping out corruption.
In 132, Sun died and was buried with great honors, including the posthumous name Gang (剛, literally "unbending").