For the trivial design and the complexity of the permission management in digital certificate-based system development, human resources are being used unwisely in writing codes of various business functions．To solve this problem, a kind of general and digital certificate-based permission management module, using function vector code, is successfully designed through analyzing and comparing the differences between digital certificate-based systems and the traditional username/password system. This kind of module can be embedded in various digital certificate-based systems by replacing the verifying module without rewriting the code, which makes the separation of permission control and transaction possible. This strategy has been tested and verified through different systems and has achieved good performance.