Network examination extends the meaning of the traditional examination, makes the examination more fair, more authoritative and reliable, accord with the modern education system, and represents the development direction of modern education examination. In order to solve the problems of the present situation that students’ scoring rate lower on the part of English vocabulary comprehension, develops a vocabulary comprehension item bank of English network examination. According to the data persistence mapping file to launch the research. Firstly, begins the design of database logical structure, designed the logical structure of "Examination question Main table", "Alternative vocabulary table" and "Standard answer table"; Then, begins the design of persistence mapping file, designs the database tables and data operation class corresponding to the mapping file which is based on NHibernate architecture. The research contents of this paper laid the foundation for the construction of item bank.