An efficient and reliable data resource authorization policy is the key of effective management, and there is no systemic study on how to make an evaluation on its efficiency and reliability. Firstly, QCC (Quantitative Cost Calculation Method) Method is proposed. Compared to the current methods, QCC makes a distinction between the wrong authorization judgment and wrong refused authorization judgment. And then a policy evaluation mechanism based on QCC is put forward. At last, by carrying out real policy evaluation analysis, we verify the effectiveness of the mechanism in improving the work efficiency with the real log data of an integrated network management system.