A new modeling parameter named link broken rate（LBR） was proposed so as to characterize the topology dy-namics.On the basis of the definition of the network dynamic characteristics parameter LBR

the expectations of the time interval between the links broken was use to measure the LBR

and a cyclic queuing model was created to analyze the characteristic of dynamic link and an analytic expression was derived.Employing the commercial simulation platform Qualnet

simulations were carried out and the model was reasonable evaluated.And the further simulation results show that

the network dynamic performance are highly related to the LBR

and the dynamic link model can integrate the mo-bility velocity

node density

and transmission range efficiently

which essentially characterize the network

and could provide theoretical results for analysis and simulation works on network dynamics.