Immobilization of Pt-based nanoparticles on carbon support is of great significance in catalysis for their superior activity and enhanced durability. Herein, we report for the first time a feasible NaCl template-engaged approach to firmly immobilize PtNi nanoparticles into two-dimensional (2D) graphitic carbon nanosheets (denoted as PtNi@GCNs hereafter). The elaborate employment of the NaCl template regulates the formation of 2D graphitic carbon nanosheets, which tightly immobilize the in situ-generated PtNi nanoparticles. The smart integration of catalytically active PtNi nanoparticles with carbon nanosheets endows the as-prepared PtNi@GCNs with superior catalytic activity and outstanding stability toward the hydrogenation of 4-nitrophenol, making them a promising catalyst for environmental remediation. We believe that the present work can inspire the future design of carbon nanosheet-based nanohybrids with unique functionalities for diverse applications.