Abstract: The development of new halide solid-state electrolyte is a research hotspot in the field of energy electrochemistry. Low ionic conductivity and poor interfacial compatibility are two major technical challenges for the exploitation of halide electrolyte. This work has focused on how to further improve the interface compatibility between the halide electrolyte of Li₃InCl₆ （LIC） and Li anode. A series of new kinds of halide electrolyte （Li₃In_1-xY_xCl₆ （0≤x≤0.5）） doped with yttrium element （Y） have been prepared by high-energy ball milling combined with annealing process subsequently. The mechanisms of element （Y） doping on Li₃InCl₆ electrolyte, including the crystal structure, thermal stability, ionic/electronic conductivity and interface compability with Li anode, are systematically explored. The testing methods contain X-ray diffraction （XRD）, scanning electron microscopy （SEM）, differential scanning calorimetry （DSC）, thermogravimetric analysis （TGA）, electrochemical impedance spectroscopy （EIS）, direct current polarization （DC）, linear scanning voltammetry （LSV）, and charge/discharge tests of the symmetrical/full batteries. The research results show that doping of Y element may reduce the room-temperature ionic conductivity of the Li₃InCl₆ electrolyte to some extent. However, incorporating an appropriate amount of Y element into Li₃InCl₆ electrolyte can lower its electronic conductivity, enhancing its thermal stability and electrochemical stability availably. It has significantly promoted the interface compatibility between Li₃InCl₆ electrolyte and Li anode by doping of Y element, enhancing the long-cycle performance of all-solid-state lithium batteries. This study provides an effective improvement strategy for designing highly stable halide electrolytes.