Abstract: Anion-immobilized solid composite electrolytes (SCEs) are important to restrain the propagation of lithium dendrites for all solid-state lithium metal batteries (ASSLMBs). Herein, a novel SCEs based on metal-organic frameworks (MOFs, UiO-66-NH₂) and superacid ZrO₂ (S-ZrO₂) fillers are proposed, and the samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), thermo-gravimetric analyzer (TGA) and some other electrochemical measurements. The –NH₂ groups of UiO-66-NH₂ combines with F atoms of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) chains by hydrogen bonds, leading to a high electrochemical stability window of 5 V. Owing to the incorporation of UiO-66-NH₂ and S-ZrO₂ in PVDF-HFP polymer, the open metal sites of MOFs and acid surfaces of S-ZrO₂ can immobilize anions by strong Lewis acid-base interaction, which enhances the effect of immobilization anions, achieving a high Li-ion transference number (t₊) of 0.72, and acquiring a high ionic conductivity of 1.05×10^–4 S·cm^–1 at 60°C. The symmetrical Li/Li cells with the anion-immobilized SCEs may steadily operate for over 600 h at 0.05 mA·cm^–2 without the short-circuit occurring. Besides, the solid composite Li/LiFePO₄ (LFP) cell with the anion-immobilized SCEs shows a superior discharge specific capacity of 158 mAh·g^–1 at 0.2 C. The results illustrate that the anion-immobilized SCEs are one of the most promising choices to optimize the performances of ASSLMBs.