In 2005, with his proficiency in sign language, he was offered the opportunity to translate for the public security bureau in Jiulongpo district of Chongqing, as they had just arrested a gang of suspected thieves, who were all deaf and mute. The police were unable to interrogate them because of the communication barrier.

Tang agreed and provided sign language translation for half an hour, and the accused confessed. In the wake of that, Tang was recruited by the bureau to help deal with cases related to deaf and mute people.

"Since communication problems often occurred in cases relating to deaf and mute people, there was often injustice. I felt heartbroken when I saw their helplessness," says Tang, who has helped in more than 1,000 cases over the years as a translator for the bureau.

"Deaf and mute people also want to play their role in the society, and in a fair way. When their legitimate interests are infringed upon, they want to find a way to sue. When they break the law, they are required to remedy their actions. But these things are all extremely difficult for them to understand," he adds.

To better help them, he decided to work as a lawyer. In 2011, he resigned from his job and enrolled at Southwest University of Political Science and Law, gaining the certificate to be a lawyer in 2012. Then, he opened his law firm and began to provide much-needed help to people in the deaf and mute community.

He says the various dialects of sign language are a major barrier in his clients' communication with others. According to him, deaf and mute people from different places learn various versions of sign language, which are very different from the standard form taught at school. Therefore, their expressions are often misread.

In 2016, an anxious woman visited Tang's office to seek help, saying her daughter had been charged with stealing, but she firmly believed her daughter was innocent. Tang rushed to the police station where the daughter was being held, and the girl also professed her innocence.

Tang then went to the local procuratorate to check the evidence for the case, and found that, due to the dialect of the sign language, the translator had misunderstood the girl's expression, and thought she had admitted guilt during her interrogation, while she actually wanted to say she was innocent. Tang's efforts saved the girl from being wrongly imprisoned.