Due to its abundant resources and advantages in transportation and storage, methane fueled solid oxide fuel cells (SOFCs) are highly needed. In this work, an exceptional internal reforming catalyst comprising in-situ exsolved NiRu bimetallic nanoparticles and oxygen-deficient layered double perovskite LaBaMn1.6Ni0.3Ru0.1O5+δ (r-LBMNR) was prepared. Compared to the cell with LaBaMn1.6Ni0.4O5+δ (r-LBMN) catalyst, the cell with a Ru-doping r-LBMNR catalyst layer, exhibits superior peak power output of 336 mW cm-2 and better durability with a less decay rate of 0.014% per hour in CH4 fuel. The enhanced electrochemical performance can be attributed to the high oxygen ion and electron conductivities of the catalyst and the coupling of Ni and Ru sites with the oxygen-deficient r-LBMNR matrix This coupling activates CH4 and H2O, promotes the oxidation of C atoms in CH4 molecules, and enables reversible hydrogen spillover, ultimately leading to the production syngas of CO(g) and H2(g).