Core-shell Fe/Al composites were successfully prepared by chemical liquid deposition with iron carbonyl [Fe(CO)5] as precursor and kerosine as oil phase medium. Scanning electron microscopy (SEM), X-ray diffractometer (XRD), and simultaneous thermogravimetry-differential thermal analysis (TG-DTA) were employed to characterize the samples and assess their thermal properties. The results indicated that the aluminum core was coated compactly by an iron layer and the the oxidation kinetics of the obtained composite powders showed a significant improvement compared to pure aluminum powders. The thermal reactivity of Fe/Al composites with oxygen is obviously higher than those of pure aluminum powders, which means that after coating much more heat can be released in the same temperature range and the heat release happens faster and more concentrated. On the basis of the results, a possible formation of the coating is proposed and a thermal reaction mechanism is also discussed.