Selective hydrogenation of C=O against the conjugated C=C in cinnamaldehyde (CAL) is indispensable to produce cinnamyl alcohol (COL), nonetheless, challenged by the low selectivity and the need to use organic solvents. Herein, for the first time, we report the use of Fe-Co alloy nanoparticles (NPs) on N-doped carbon support as a selective hydrogenation catalyst to efficiently convert CAL to COL. The resultant catalyst with the optimized Fe/Co ratio of 0.5 can achieve an exceptional COL selectivity of 91.7% at a CAL conversion of 95.1% in pure water medium under mild reaction conditions, ranking it the best performed catalyst reported to date. The experimental results confirm that the COL selectivity and CAL conversion efficiency are respectively promoted by the presence of Co and Fe, while the synergism of the alloyed Fe-Co is the key to concurrently achieve high COL selectivity and CAL conversion efficiency .