The ever-decreasing fossil fuels and the increasing greenhouse effect have caused substantial concern. Solid oxide electrolyser cell (SOEC) with La_0.75Sr_0.25Cr_0.5Mn_0.5O_3-δ (LSCM) as a cathode was used for CO₂ electrolysis to CO. In this work, the metal-oxide interface was constructed on the LSCM framework by in-situ exsolution and impregnation, and the uniform distribution of metal nanoparticles on the LSCM framework was confirmed by spectroscopy techniques and electron microscopy techniques. The existence of three-phase boundary promoted the absorption and electrolysis of CO₂. (La_0.75Sr_0.25)_0.9(Cr_0.5Mn_0.5)_0.9(Ni_0.5Cu_0.5)_0.1O_3-δ (LSCMNC) showed the best electrolytic CO₂ performance at 850 ℃ and exhibited excellent electrocatalytic activity after 100 hours of long-term testing and 8 redox cycles.