The status of development of the technology of environmental control system(ECS) for avionics pods was introduced, a new type re-cool reverse boot-strap ram air circle cooling scheme of ECS for pods was brought forward. The optimum design mathematical models of typical ECS for pods were created, and the optimum method was discussed. Four types of ECS presently used in military aircraft pods were considered. The sine method combined with simplex method was applied to seek optimal technologic scheme and parameters for these systems. Finally the contrasts and analysis of the results of the system scheme and parameter optimization were made. The results showed that the new pod ECS had less fuel penalty and higher Coefficient of Performance(COP).