Developing stable conductive materials with high conductivity for sodium ion (Na+) batteries attracts ever-increasing attention. In this work, MOF-based solid Na+-conducting composites functionalized by ionic liquids (ILs) were explored through introducing five kinds of ILs and their corresponding sodium salts into the pores of MIL-101-SO3Na. The pore-filling fraction of MIL-101-SO3Na was established and revealed as a key factor to enhance the ionic conductivity of the composites. Na-salts could further improved the conductivity by increasing the number of conductive ions. Furthermore, all ILs and [email protected] hybrid composites showed sharply enhanced ionic conductivity and displayed low activation energy. Particularly, as the pore-filling faction elevating to 96.94 % with [Emim][BF4] and NaBF4 in the pores of MIL-101-SO3Na the ionic conductivity reached up to 1.32x10(-2) S cm(-1) and stabilized within 30 days at 150 degrees C. This study on Na+-conduction in a MOF-based system functionalized by ILs, providing guidance for exploring new solid ionic conducting materials.