Abstract: With the rapid development and extensive use of complex information system on both
military and civil field, design of the display interface of complex information system needs to be
improved to a higher level. The usability evaluation can be used to guide the improvement of the
interface design of complex information system, which can reduce the workload of users induced by
the complexity of system, and also improve the performance of users. This has already become a
problem demanding prompt solution. This paper researched on the complex information system
interface and analyzed from the features of interface, task and cognition, after which, the influence
factors of interface complexity were put forward, the index system of complexity evaluation was
constructed and the index weight of the complexity of interface was studied by AHP, and in the end,
the corresponding usability index system was put forward according to the complexity model.

Key words: complete information system, usability, analytic hierarchy process, index system