The Fischer-Tropsch (FT) synthesis, as an alternative route to produce high-quality liquid fuels and chemicals, has received considerable attention in recent years. In this work, a nano-sized capsule catalyst (ZrO2@FeCu) with ZrO2 as a core and FeCu bimetallic oxide as a shell was fabricated by urea hydrolysis method. For comparison, FeCu@ZrO2 capsule catalyst was synthesized by the sequential precipitation method. FeCu + ZrO2 reference catalyst was obtained by physically mixing of FeCu and ZrO2 samples. Besides, these catalysts with potassium (K) modification were realized by wetness impregnation method, and the catalysts are denoted as ZrO2@FeCu-K, FeCu@ZrO2-K, and FeCu + ZrO2-K, respectively. The structure-function relationship of the obtained catalysts was systematically clarified by means of a series of characterization techniques, such as BET, XRD, H-2-TPR, CO-TPD, XPS, SEM and EDS mapping. Among these catalysts after reduction, ZrO2@FeCu-K exhibited the most excellent catalytic performance with 97 % CO conversion and 49 % alpha-olefins selectivity by promoted CO adsorption.