Cubic phase stabilization is extremely important for the application of cesium lead halide inorganic perovskite materials into fabrication of perovskite solar cells. Methods on how to stabilize inorganic perovskite phase have been discussed in this review. The increase of surface energy of perovskite grains can stabilize the cubic perovskite phase simply by decreasing the grain size or reducing the dimension of perovskite crystals. The substitution of cations or anions in the perovskite crystal lattice by different elements, followed by the rule of Goldschmidt tolerance factor, can also produce stable inorganic perovskites with enhanced electronic and optical properties. Meanwhile, an abundant choice of appropriate elements for the substitution can fundamentally enrich the library of stable inorganic perovskites.