The employer formulates internal labor discipline norms to manage the work behavior of the employee according to its industry, development requirements, and production and operation model, etc. When the employee has an act of undermining the order of production and operation, the employer may exercise the disciplinary power in accordance with these rules and regulations to achieve the stability of the production and operation order of the employer and the maintenance of the company's interests. However, in practice, due to the lack of corresponding regulation of the disciplinary power, and the fact that the degree words in the corresponding legal provisions are not clearly defined, the employer's disciplinary power is easily abused, becoming a weapon to infringe on the interests of employee. The contradiction between employers and workers is deepening. As the"imperial principle" in the field of administrative law, the proportional principle, whose purpose is to regulate discretion and protect the interests of the counterparts, is of great significance for determining the standard of degree. Therefore, the principle of proportionality is introduced into the labor laws and regulations to regulate the disciplinary power of employers, so as to alleviate the contradictions between employers and employees. The paper studies its value, application possibilities, and specific mechanisms for regulating the disciplinary power of employers, in order to put forward suggestions for improving the disciplinary power of employers.