Abstract: The practical rationality of the case discussion mechanism represented by the Adjudication Committee is increasingly affected by social situation factors, which has resulted in the functional limitation of the decision-making mechanism of the Adjudication Committee. In the process of the gradual changing of the actual role of the Adjudication Committee, the discussion process of judges’ meeting gradually emerged and was institutionalized. The “positive and negative verification” function of judges’ meeting has solved the problem of authoritative source of law application in difficult cases, and largely replaced the function of the judicial committee to regulate the application of law. The change of the discussion mechanism in the internal court reflects the difference in the concentration of power within the court. It reflects the change from the limited function of the Adjudication Committee to the institutionalization of judges’ meeting, and also reflects the process of power change from collective decision-making power to collective discussion power. Correspondingly, the trial power of the judges group is more autonomous, and the process of collective rationality moving toward individual rationality is strengthened.