Dry reforming of methane (DRM) is a feasible solution to address the reduction of greenhouse gases stipulated by the Paris Climate Agreement, given that it adds value by converting trivial gases, CO2 and CH4, simultaneously into useful syngas. However, the conventional Ni catalyst undergoes deactivation due to carbon coking and particle agglomeration. Here we demonstrate a highly efficient and durable DRM catalyst: exsolved Co‐Ni‐Fe ternary alloy nanoparticles on the layered perovskite PrBaMn1.7Co0.1Ni0.2O5+δ produced by topotactic exsolution. This method readily allows the generation of a larger number of exsolved nanoparticles with enhanced catalytic activity above that of Ni monometallic and Co‐Ni bimetallic particles. The enhancement is achieved by the upshift of the d‐band center of Co‐Ni‐Fe relative to those of Co‐Ni and Ni, meaning easier charge donation to the adsorbate. Furthermore, the exsolved catalyst shows exceptional stability, with continuous DRM operation for about 350 hours. Ternary Co‐Ni‐Fe nanoparticles were produced by topotactic exsolution. Compared bimetallic and monometallic catalysts, the ternary Co‐Ni‐Fe catalyst exhibited enhanced catalytic activity for the dry reforming of methane. DFT calculations indicated the enhanced activity originates from the optimal upshift of the d‐band center of Co‐Ni‐Fe catalyst.