Porous Li2MnSiO4/C nanocomposite has been synthesized via a solid‐state reaction using rice husks as raw material, in which cubic‐like Li2MnSiO4 nanoparticles are uniformly distributed in the porous carbon layer, as high stability and capacity lithium‐ion cathode materials. Compared to Li2MnSiO4/C, the as‐prepared porous nanocomposite delivers a high initial discharge/charge specific capacity of 479.6/321.9 mAh g−1 at 0.2 C and a superior cycling stability (276.9/242.2 mAh g−1 at 0.2 C after 50 cycles of charge‐discharge cycle). In addition, the porous Li2MnSiO4/C exhibits an excellent rate performance that it still has a discharge specific capacity of 163.2 mAh g−1 even at 1 C. Its outstanding electrochemical properties are attributed to the unique porous carbon nanostructure, which not only improves the conductivity of the material, but also facilitates the transfer of ions in the material. This facile and low‐cost of porous Li2MnSiO4/C cathode material has great potential in the future development of lithium ion batteries.