In the process of integrating the Chinese market with the international market, the Pay Secrecy Rules has been gradually introduced. Fettered by cognition-inconsistency in practice regarding the legal nature of the rule and the sweeping use of the rule by employers, disputes over dismissal due to violation of the rules are increasing year by year. The courts have seen large divergences in the legitimacy adjudication of dismissal. After clarifying the legal nature of the rule with the help of 20 typical cases, on the basis of referring to the "three-step analysis method" of the United States and the reality in China and the existing legal system, it is recommended to adjudicate the legitimacy of dismissal for breaching Pay Secrecy Rules as below: Only if the content and the formulation procedure of the rule are legal, can it be used to determine the rights and obligations of both parties in the labor relations; otherwise the rule itself is illegal, and the dismissal decision based on the rule is also illegal. The dismissal decision should conform to the "principle of proportionality", that is, the dismissal decision should be commensurate with the gravity of the consequences caused by the infringement of the employee, otherwise the dismissal is illegal