Due to the extensive use of ferrite in nuclear power plants, the thermal aging issues of ferritic alloys have attracted significant attention. The present study investigates thermally aged FeCr binary ferritic alloys with different Cr contents using various mechanical and magnetic properties tests. The result indicates that the increase in Cr element content and prolonged thermal aging significantly enhances the strength of alloy materials, along with an important reduction in toughness. Meanwhile, the magnetic characteristic shows a considerable difference in different ferritic alloys with varying Cr contents under the influence of thermal aging. As a potential characterization method, magnetic measurement can be used to determine the thermal aging degree in ferritic alloys and the Cr concentration should be considered.