Abstract: Security requirements’ diversity demands the flexibility and scalability of security policy, but traditional operating systems implement security policies in many components so that it is difficult to meet the needs. A policy-flexible system framework is brought forward through the analysis of all the facilities related to security policy in the system, and this framework is implemented based on Linux. Compared with the previous researches, the framework simplifies policies conflict mediating by centralized management of security attributes. So this framework can support users in configuring security policies flexibly, and add new security policies based on new security attributes according to security requirements in their fields.