Abstract: UCON (Usage Control) is able to cover access control, trust management and DRM (Digital Rights Management) and called the next generation access control model. However, its practical application is still in the exploratory stage because of its mandate is complex. The author removes the obligation element and splits condition element to simplify the implementation. At the same time, author puts forward three basic control modes which can meet the needs of cross-domain access control in the cloud computing environment.