Abstract: Safety is very important for construction of the campus network work.PKI technology,as one kind of public key infrastructure,has provided a frame,under which the encrypted campus network work safety service can be implemented.In this paper,the security problems and requirements of the Jishou university network work system are  firstly analysed;and then a kind network work model  of Jishou university based on the mixed trust model and PKI is designed.

Key words: campus network work system, level trust model, overlapping trust model, PKI