Fundamental understanding of the synergistic effect of bimetallic catalysts is of extreme significance in heterogeneous catalysis, but a great challenge lies in the precise construction of uniform dual‐metal sites. Here, we develop a novel method for constructing Pt1−Fe1/ND dual‐single‐atom catalyst, by anchoring Pt single atoms on Fe1−N4 sites decorating a nanodiamond (ND) surface. Using this catalyst, the synergy of nitroarenes selective hydrogenation is revealed. In detail, hydrogen is activated on the Pt1−Fe1 dual site and the nitro group is strongly adsorbed on the Fe1 site via a vertical configuration for subsequent hydrogenation. Such synergistic effect decreases the activation energy and results in an unprecedented catalytic performance (3.1 s−1 turnover frequency, ca. 100 % selectivity, 24 types of substrates). Our findings advance the applications of dual‐single‐atom catalysts in selective hydrogenations and open up a new way to explore the nature of synergistic catalysis at the atomic level.