The leniency system of pleading guilty and punishment gives the defendant both procedural and substantive leniency to encourage them to voluntarily plead guilty and punishment. The defendant who pleads guilty has the right of appeal. It is not only the protection of his personal rights and interests, but also the inherent requirement of the reform of the "trial centered" system. Although the defendant's appeal to a certain extent is the overthrow of the first instance procedure, the development of the system is not perfect at this stage, and the investigators have some problems, such as one-sided understanding and lack of experience. At present, it is unrealistic to completely deprive the plea defendant of the right of appeal. However, from the long-term perspective of the development of the system, it is the inherent requirement to limit the right of appeal of the guilty defendant. In order to balance the contradiction, we should take the basic national conditions of our country as the basis, make confession and punishment voluntarily for the defendant outside, improve the corresponding guarantee conditions, list the reasons for appeal inside, and learn from the regulations of foreign countries on the limitation of the defendant's right of appeal under the corresponding system reasonably, so as to better implement the confession and punishment in judicial practice leniency system.