Aiming at the issue of the performance of routing protocols in Mobile Ad Hoc Network affected by node density,relativity of routing efficiency and node density is studied.

Nodes remaining energy is considered in the new protocol,relying on node s remaining energy RREQ delay is adjusted,and the algorithm of avoiding route breaks is used in the new protocol,flooding broadcast is optimized by the restriction that the last time that nodes delivering data packet.

Under the model, this paper introduces the concept of a link to be Υ-valid- time, derive the probability for a link to be valid and obtain the conditional probability for a route to be valid and the average times .

On the basis of the probabilistic routing, combines with network coding and refers to the thinking of single copy, Spray and Wait routing, we proposes an improvement protocol: Extended Probabilistic Routing base Network Coding (EXPR-NC) in which nodes directly forward packets without copying and establish a neighboring nodes list for each node.