Usually, the same person should not be the agent of the plaintiff and defendant in the same litigation case at the same time, especially a full-time legal worker like a lawyer.
Article 47 of the People's Republic of China (PRC) Lawyers Law.
If a lawyer commits one of the following acts, the judicial administrative department of the people's government at the municipal level or municipality directly under the Central Government shall give him a warning and may impose a fine of not more than 5,000 yuan; Illegal income, confiscate the illegal income; If the circumstances are serious, the punishment of stopping practicing for less than three months shall be given:
(3) Representing both parties in the same case, or representing legal affairs that have conflicts of interest with himself and his close relatives;
Extended data
Article 9 of the Measures for Punishment of Illegal Acts of Lawyers and Law Firms? If a law firm commits one of the following acts, it shall be given a warning by the judicial administrative organ of the province, autonomous region or municipality directly under the Central Government, and its illegal income shall be confiscated, and it shall be suspended for rectification for more than 3 months 1 year:
(fifteen) the same case, the appointment of lawyers for both parties or parties with conflicts of interest to represent and defend, but there is only one law firm in the county (city), except with the consent of both parties.
Baidu Encyclopedia-People's Republic of China (PRC) Lawyer Law
Baidu Encyclopedia-Measures for Punishment of Illegal Acts by Lawyers and Law Firms