This paper explores the methods and applications of intuitive visualization and interactive analysis of medical domain knowledge to help medical experts editing it autonomously. SissiExpression system is developed using C# and WPF technology, in which, medical knowledge is modeled as expression. The application of knowledge and execution process is clear and visible, the work of debugging and maintenance is convenient, so the result can be understood and gain recognition by experts. Expressions and knowledge are saved in XML file format, decoupled from program framework, subsequent maintenance, adding new knowledge and functions, can be achieved agilely, conveniently, with better cost control. Appropriate knowledge edition can be chosen flexibly according to demand, medical experts can possess their personal executable knowledge base. This program can help medical experts to mitigate human-computer interaction obstacles to some extent, both medical and information experts can focus on their own profession and tasks.