A novel model is put forward which represents combat behavior and network behavior in an unitary form, the evolving network for the combat on the battlefield F_R,Bis constructed jointly by generating a random network on f_R,Band removing nodes from fighting forces' networks, under the condition that the assumptions of Lanchester Model is generalized, and represented as a triple of networks F_R,B=forces R's network I_R∪ forces B's network I_B∪ engagement space f_R,B.In the model the effectiveness of a networked forces relates not only its size and the weapon performance, but also the structure of network and the battlefield in which it operates. An experiment shows that with the same operational assets a scale-free network is more dominant than a random network for both information effectiveness and killing rate but not always wins, the origin is analyzed that the scale-free network is efficiency，robust yet fragile in the conflict system.