This paper presents a new algorithm for the consistency of information based on the average state, and it is applied in first-order system and second-order system. Frequency domain analysis method is used to obtain sufficient conditions for the convergence rate. Due to the inevitable presence of the communication network itself and the other individual time lag problems between individuals, the paper further analyzes the stability of the system under time delay which uses the proposed consistency algorithm. For second-order multi-agent system, firstly, consensus algorithm of average state under the undirected network is proposed and based on the given conditions, sufficient conditions are obtained under which the system achieves static consistent and dynamic consistent. Finally, the algorithm is applied in a multi-aircraft formation control groups.