In recent years,the ad hoc network has been paid extensive attention due to its characteristics of non-center and self-organization.Firstly this paper introduces three typical routing protocols AODV,DSDV,DSR,and the principles of them; then,adopts the NS2 simulation platform to simulate the performance of end-to-end delay,routing overhead and packet delivery ratio by changing the number of nodes and the paused time of nodes.Finally,by comparing the simulating results, the comparison conclusion is provided.