The invention relates to the field of lithium batteries, in particular to a solid electrolyte and a lithium battery cell with the solid electrolyte, and a lithium battery. The solid electrolyte comprises Li3Sn2(PO4)3 and/or Li3Ge2(PO4)3. The solid electrolyte has a stable structure, has an electrochemical window of above 5V, has better adhesion and flexibility, and has better interface wettabilityand interface adhesion when contacting an electrode layer. The Se and Ge atoms in the structure of the solid electrolyte are weakly bound to Li+, so that the Li ions are easier to migrate, and betterconductivity can be obtained. Furthermore, based on the structural characteristics, the solid electrolyte has the advantages of high shear modulus, high Young's modulus and capability of inhibiting the growth of lithium dendrites.