Yao started to practice Falun Dafa in 1996. He went to the Beijing People's Appeal Reception Office in 1999 to appeal for Falun Dafa and was sentenced to three years of forced labour that was to be carried out in the Huludao City Forced Labour Camp.

At the end of February 2001, he was transferred to Wujiabaozi Forced Labour Camp in Fushun City. With the permission and support of the head of the "Mental Correction" (brainwashing) Team, Jiang Yongfeng, the second in command planned and organized to seriously persecute Yao, in both the men's and women's team, in order to force him to give up his belief. Yao has given the following descriptions of his experience:

The persecution started at the First Class of the team. They used physical punishments such as squatting, bending down with hands stretched behind the back, punching and kicking etc. They whipped him with shoes and belts and used electric batons to shock him. In April, the police took him to the Sixth Class of the woman's team during the day and brought him back to the men's team in the evening to torture him in turn. Once he lost consciousness from the beating, yet they carried him to the women's team the next day to continue the torture. Several days after, his body was covered with wounds and his head was very swollen. His face was distorted beyond recognition. His back had been injured and his urine contained blood. His hands were swollen from repeated beating and torture. There were many bloody holes left in his fingers and soles from being stuck with needles. They tickled his armpits, ribs, and soles etc. to make him laugh uncontrollably. However, he still refused to write any material to renounce Falun Gong despite various torture methods. They tied his hands and his feet together behind his back and tucked him head down facing a corner. That evening, Yao could not walk and had to be carried back. The next day, they carried him to the women's team again to be tortured. At first, they loosened the rope every one to two hours. Later, they increased the time gradually and Yao's sweat from the intense pain soaked his clothes.

During this time, Jiang Yongfeng came several times to inspect. He often sent people from the men's team to monitor his progress and help with the torture. When he was in the most pain, Yao called loudly for help but nobody ever came, despite the fact that he was less than ten meters from the on-call guard and less then twenty meters from the head's office. Song Jingyang and Yang Xiaohong tortured him and told him, "This is the result of orders from above. It is no use for you to shout." Yao was in such a pain that he knocked his head against the wall. His blood stained the wall. However, the evil people did not loosen the rope and continued the torture after putting newspapers around his head. This would often go on for as long as six hours.

The last time Yao was tortured with the rope, his legs became paralysed. His calves went soft, his heel tendons could not be felt, and his feet lost all sensory and motor functions completely. Over the next several months Yao became bedridden and had to have two people holding him to go to the toilet. They did not send him to the hospital in time. Yao talked to Jiang Yongfeng [about his situation], but they did not stop the torture. Instead they refused to allow Yao to sleep for 8 or 9 days at a stretch. During this time, Yao suffered extreme damage both physically and mentally and was nearly at the edge of collapse. Another Falun Dafa practitioner in similar circumstances, Yao Songdong, was unable to tolerate such torture, had a mental collapse and was sent to a mental institution.

On April 19, 2001, they finally sent Yao Yanhui to a hospital affiliated with Fushun Mining Bureau. The doctor diagnosed him with "sciatic nerve damage" and recommended hospitalisation. However, the camp did not allow this and carried him back. He only received some simple treatments.
Since the injuries on his legs and feet would not heal for a long time, Yao appealed again in October 2001 and talked many times with the authorities to request treatment outside of the Forced Labour Camp. Yet the camp officials put off his requests again and again, saying that he could go for treatment but never actually allowing it. Therefore, on February 4, 2002, Yao started a hunger strike to speed up the process. The Forced Labour Camp continued to ignore him. At the beginning of March, Yao appealed to Fushun City People's Court and asked the camp to pass on a letter he had written to the Court. He did not hear anything thereafter. After several weeks, Yao demanded a meeting with the chairman of the Forced Labour Camp, Xu Hulie. Xu never came. He then asked to see the in-house Chief Inspector, Wang Junfu. The camp did not accommodate his request. Now Yao has been on hunger strike for more than two months yet the officials at the forced labour camp continue to ignore him.