A plan deduction system is developed to support multiple real-time data transmission satellite reconnaissance missions. The overall structure and information flow of system are designed, followed by research about the key technologies needed for system development. A data transmission task planning algorithm for area reconnaissance, a satellite area coverage analysis algorithm based on grid, a visualization method for target area and reconnaissance scope based on OSGEarth are proposed. The developed planning and deduction system has been successfully applied to an unnamed task to carry out the task planning, capability analysis, and process deduction.