Abstract: The No.50 of the PRC Administrative Procedure Law dearly states that "mediation shall not apply to administrative proceedings". Reconciliation in the name of settlement widely exists in practice. More and more people call for the establishment of a settlement regime in administrative proceedings. Formulation and justification are not the main obstacles to the establishment of settlement regime in administrative proceedings. Collusion in Administrative Litigation Settlement is the key issue. Through game theory and case analysis, we found that there may be different types of collusions in administrative litigation settlement. It is not conducive to social stability and the role of judges will be compromised. When building the administrative litigation reconciliation system, we should take measures to control the collusions in administrative litigation settlement. The separation of settlement and trial is helpful to judicial neutrality. Improving the prior-execution and enforceability of settlement agreement will be conducive to preventing post-decision disputes, and it is necessary for us to create the right of continual trial to protect legal rights of prosecutors who have applied for withdrawal of charges.