Serious and complex joint criminal cases have their own special characteristics while Pleading Guilty and Accepting Punishments with Leniency system emphasizes the efficiency of litigation. In this sense, although this system is usually adopted in ordinary cases at any stage of litigation, it cannot be applied to serious and complex joint crimes just in case that potential problems caused by the voluntariness and truthfulness of confession are concealed, which may affect the conviction and sentence or even the fairness and justice. When applying Pleading Guilty and Accepting Punishments with Leniency in serious and complex joint crime cases, we should adjust the procedure based on the principle of "justice first and full consideration of efficiency", build a procedural diversion mechanism and fact-finding mechanism led by the prosecution office, and strive to achieve both justice and efficiency in litigation.