In view of the insufficiency of central air-conditioning system that FCU, water pumps and air blower’s movement connot match with the actual operating load when varying duty, an energy saving control system for central air-conditioning based on terminal temperature measuring and frequency conversion control technology is proposed. This system can real-time measure different floors’ and nods’ temperatures in the building, and export orders to control the frequency of FCU, chilled water pump, cooling water pump and cooling tower air blower. To overcome big delay, large inertia and variable condition of control object, the dnamic fzzy nural network algorithm(DFNN), is applied into the control system. According to the practical running situations, the energy saving control system has advantages as high energy saving rate, high stability, good maintainability, which may be promoted the application vigorously.