The invention relates to the technical field of steam power devices, and discloses an air exhaust system for a steam power device. The air exhaust system comprises a first-level main air exhaust device, a second-level main air exhaust device, a steam sealing air exhaust device and an integrated cooler, wherein a first-level cooling section, a steam sealing cooling section and a second-level cooling section, which are mutually independent, are arranged in the integrated cooler; the inlet of the first-level main air exhaust device is connected with a condenser air exhaust pipeline, and the outlet of the first-level main air exhaust device is connected with the inlet of the first-level cooling section; the inlet of the second-level main air exhaust device is connected with the outlet of the first-level cooling section, and the outlet of the second-level main air exhaust device is connected with the inlet of the second-level cooling section; the inlet of the steam sealing air exhaust device is connected with the outlet of the steam sealing cooling section, and the outlet of the steam sealing air exhaust device is connected with the inlet of the second-level cooling section; and the inlet of the steam sealing cooling section is connected with a shaft sealing air exhaust pipeline. The air exhaust system for the steam power device is convenient in intensively providing working steam and recovering condensed water of which the apparent contact angle is greater than 90 degrees, so that a space occupied for installation is greatly reduced, system pipeline complexity is lowered, and system design difficulties are lowered.