The synthesis of Pt-based nanoparticles (NPs) with ultrasmall feature and tailored structure is of great importance for catalysis yet challenging. In this work, we demonstrate a facile top–down strategy for the fabrication of small-sized Pt-based intermetallic compounds (IMCs) with L1₀ structure through the evaporation of Cd under high temperature. Impressively, such thermal treatment can be used as a versatile strategy for creating binary, ternary, quaternary, quinary, and senary L1₀-Pt-based IMCs. Moreover, the small-sized Pt-based IMCs display high stability against high temperature of 700 °C, which can serve as active and selective catalyst for the selective hydrogenation of 4-nitrophenylacetylene. This work may not only provide a versatile top–down strategy for fabricating highly stable small-sized Pt-based NPs with L1₀ structure, but also promote their extensive applications in catalysis and beyond.