Sun Lancheng was a 41-year-old female practitioner from Dingzhai Village, Shaogu Township, Wei County, Hebei Province. Since the persecution of Falun Gong began on July 20, 1999, she had gone to Beijing many times to appeal. As a result, she was arrested, had her home ransacked, and was fined huge amounts many times.

On New Year's Day in 2001, she once again went to Beijing to appeal. She was arrested and taken back to Wei County by the county police department. Later she walked out of detention with righteous thoughts. In order to avoid further persecution, she had to leave home and wander about together with her husband, also a practitioner. Around August or September in 2001, she was arrested again by Qinghe County Police Department in Hebei Province while protecting fellow practitioners at a truth-clarification material production site. She was detained in a detention center for over nine months. During detention, she went on hunger strikes many times to protest. Because of the long-term persecution, she became extremely weak. The police planned to send her to a labor camp, but the labor camp refused to take her because of her poor health. The police had to take her back to the detention center. She once again went on hunger strike. The police sent her to a hospital to be force-fed. While detained in the hospital, she managed to escape.

One day in December 2002, while she was attending an experience-sharing conference, she was arrested again. The police sent her to a labor camp, but the labor camp refused to admit her because of her poor health. The police had no alternative but to send her home. Not long afterward, she passed away at home on February 3, 2003.