First of all, according to Article 52 of the Company Law, "directors and senior managers may not concurrently serve as supervisors." The chief financial officer belongs to the senior management of the company;
Secondly, according to Article 54 of the Company Law, "The board of supervisors and supervisors of companies without a board of supervisors shall exercise the following functions and powers: (1) Check the company's finances;
One of the duties of supervisors is to check the company's finances, so generally speaking, financial personnel can't be supervisors, otherwise it is meaningless to supervise themselves.