In order to find out the micro factors that impact user’s satisfaction about library websites, this paper puts forward a flexible self-evaluation system. With this system, the library websites can choose suitable micro evaluation plan according to their own needs, and diagnose by themselves the underlying factors that impact user’s satisfaction. The system is highly user-definable, and the library managers can create experts’ weight-surveying questionnaires by using its indicator templates or by using self-defined indicators. Finally, the surveying data are analyzed and showed with 3D visualization graphics, and the micro factors needs to be improved are found out.