Abstract: An energy-saving sludge drying disposal system is provided. The disposal system includes a vacuum heating unit, an incinerating unit, a vacuum cooling unit and a molten salt heat exchanging unit. The vacuum cooling unit includes a high-temperature gas inlet, a condensed water outlet, a low-temperature gas outlet, a low-temperature liquid inlet and a medium-temperature liquid outlet. The high-temperature gas inlet of the vacuum cooling unit is connected with the vacuum heating unit. The incinerating unit includes an incinerator, an incineration gas inlet, a combustion-supporting gas inlet, a flue gas discharge outlet, a cold molten salt inlet and a hot molten salt outlet. The incineration gas inlet is connected with the low-temperature gas outlet of the vacuum cooling unit. The molten salt heat exchanging unit includes a cold molten salt outlet, a hot molten salt inlet, a medium-temperature liquid inlet and a high-temperature liquid outlet.