Is it illegal for banks to let regular employees be cleaners?

It is not illegal for banks to let regular employees be cleaners.

The staff in the bank are formal employees who have passed the annual recruitment examination of public institutions, and the employers who have passed the examination of labor service companies are informal employees, also called labor dispatch personnel.

There are two kinds of bank staff: one is the formal staff of the bank (also known as the internal staff of the bank), and the other is the labor dispatch agreement worker. The formal employees of banks, that is, the formal employees in the establishment of banks, are simply employees who sign formal labor contracts with banks. Enjoy the normal salary stipulated in the contract, various welfare subsidies and performance bonuses, and have many promotion opportunities. Probation period personnel and temporary employees are not included.

Bank dispatch workers, that is, dispatch contracts are only signed with dispatch companies, which is equivalent to temporary workers. The dispatching company sends you to work in the bank, and the bank gives your salary and bonus to the company. Generally speaking, you work in a bank, but you are not an employee of the bank. You just sent the company to the bank to do auxiliary work, and there was no chance to enter the management. Their wages and benefits are lower than those of regular bank workers, and their bonuses are generally the same.