Policy refinement is an important technology to resolve the configuration complexity of access control policies in distributed applications. Existing methods for policy refinement describe and refine policies layer by layer. However, they are weak in dealing with the relationship between policies. In this study, policies and the relationship between them are described based on the policy refinement tree where policies conflict analysis is performed on the leaf nodes to allow using R-refutation calculus of open logic to analyze refinement policy correlation properties. This method can resolve conflicting policies while correctly maintaining mutual exclusion, combination, access path coordination, and refinement mapping of policies. It can also resolve conflicting policies of different types in order, and freely make a choice among conflicting policies. Experiments and performance analysis demonstrate that the presented method meets the need of dynamic adaption of policy refinement for service-oriented application systems on SaaS platform.