In view of the defect that network DEA (data envelopment analysis) can not reflect the network structure when it comes to dynamic evaluation, we proposed a two-stage evaluation method of dynamic network DEA. Time parameter was introduced to network DEA and dynamic network DEA model was established. In order to evaluate the efficiency of dynamic network DEA in several time spans, we built a two-stage evaluation method. In the first stage, dynamic network DEA efficiency matrix was formulated. In the second one, a new input-output DEA unit was set up to evaluate the synthetical efficiency of dynamic network DEA. The two-stage method can manifest the real dynamic property in network DEA, as well as consider the network structure which involves intermediate products by dynamic measure. A numerical example indicated that the two-stage evaluation method can solve dynamic network DEA problem efficiently, it can also provide improved information between inefficient DMU and optimum values by slacks. The new measure can be a good tool of systems analysis.