In his late career, Cheng was expelled from the Chinese Communist Party in 2003 after a corruption investigation.

In January 2003, Cheng resigned as Chairman of the Hebei People's Congress and immediately headed back to Changzhou.

He then lived in a mansion-complex named Yuyuan (愚园) for the remainder of his life.

In August 2003, following an investigation by the Central Commission for Discipline Inspection, Cheng was expelled from the Chinese Communist Party for violating party discipline by aiding and abetting activities of his son and others.

[4] Until the corruption case of Hebei party chief Zhou Benshun in 2015, Cheng was the only Hebei party leader in history to have been accused of corruption-related offenses by the party's top disciplinary body, the Central Commission for Discipline Inspection.