Criminal severance of cases is a common and flexible procedural mechanism in judicial practice for handling joint criminal cases, which plays an important role in ensuring the quality of criminal prosecution, improving the efficiency of case handling, and safeguarding the rights of the prosecuted. However, many problems have arisen in the operation of judicial practice in the separate case handling. For example, the subject of the decision is unreasonable, the application standards are not unified, the supervision mechanism is insufficient, and the rights of the parties are not protected, etc., resulting in the application of Severance of cases is chaotic, the procedure is not standardized, all kinds of functional alienation phenomenon, has significantly deviated from the track of the rule of law. In response to these issues, it is necessary to adjust the initiation method of severance of cases, clarify the scope of severance of cases, and unify the applicable standards for severance of cases. In terms of supervision mechanisms, external and internal supervision mechanisms should be established and improved to provide parties with scientific and reasonable judicial remedies, effectively preventing the abuse of power. The ultimate goal is to unify the rights and responsibilities of the judicial practice of approving separate cases, reduce the abuse of the right to try separate cases in practice, and truly realize the value of the separate case trial system.