Summary Polymer solid electrolyte with high ionic conductivity at room‐temperature is most likely to be widely used in solid‐state lithium batteries. In this work, the novel surface lithiated TiO2 nanorods were firstly used as ionic conductor in polymer solid electrolyte. The surface lithiated TiO2 nanorods‐filled polypropylene carbonate polymer composite solid electrolyte (CSE) has an uniform composite structure with a thickness of about 60 μm. The ionic conductivity at room‐temperature is 1.21 × 10−4 S cm−1 and the electrochemical stability window is up to 4.6 V (vs Li+/Li). The assembled NCM622/CSE/Li solid‐state battery shows a stable cycle performance with a retention capacity of 120 mAh g−1 after 200 cycles at the current density of 0.3 C and a high coulomb efficiency of 99%. Compared with TiO2 particles, this novel surface lithiated TiO2 nanorods can provide more continuous ion transport channels and more Lewis acid‐base reactive sites, provide a novel way to enhance the lithium ion transport in polymer solid electrolyte.