After Rules about the People's Court Publishing Judgment Documents on Internet issued by the supreme people's court comes into effect, eligible documents has been mostly public-based. Existing public, however, stops at formality, open about magistrate reason, which is related to substantive equality, is not in place. There are a lot of civil judgment documents lacking of logicality, evidence synthesis, and explanation of applicable law. After analyzing principal, content, method and language rules of open reasoning, we propose establishing and improving case guidance system, technical specifications, judge responsibility and documents evaluation mechanism to guarantee public of magistrate reason.