Abstract: Inorganic halide perovskite solar cells (IHPSCs) have become one of the most promising research hotspots due to to the excellent light and thermal stabilities of inorganic halide perovskites (IHPs). Despite rapid progress in cell performance in very recent years, the phase instability of IHPs easily occurs, which will remarkably influence the cell efficiency and stability. Much effort has been devoted to solving this issue. In this review, we focus on representative progress in the stability from IHPs to IHPSCs, including (i) a brief introduction of inorganic perovskite materials and devices, (ii) some new additives and fabrication methods, (iii) thermal and light stabilities, (iv) tailoring phase stability, (v) optimization of the stability of inorganic perovskite solar cells and (vi) interfacial engineering for stability enhancement. Finally, perspectives will be given regarding future work on highly efficient and stable IHPSCs. This review aims to provide a thorough understanding of the key influential factors on the stability of materials to highly efficient and stable IHPSCs.