Abstract: In order to realize the intelligent question answering system for disease diagnosis and treatment in medical informationization, this article proposed a method for understanding the user'question described by nature language based on human-computer interaction.On the basis of the Keywords library, the method use the maximum matching algorithm for lexical analysing of the user consulting.And then classify the issues of medical field, the system take the data retrieval according to the categories of issues.The system will also use the method of template matching for extracting the answer, with the sentence as the basic unit of answer.Finally, intelligent question answering system of medical field is realized based on B/S model on the platform of JSP and JAVA, it prove the effectiveness of this method.