All inorganic perovskite nanocrystals with narrow-emission, high quantum efficiency and high carrier mobility have been widely applied in the fields of light emitting diodes and solar cells. However, present surface ligands of the perovskite nanocrystals are in a dynamic bonding state, which easily fall off during separation and purification processes, resulting in the deterioration of quantum efficiency and stability. Besides, the ionic characteristic of halide perovskites makes it extremely sensitive to polar solvents. These disadvantages severely restrict the practical application of perovskite nanocrystals in optoelectronic devices. In this review, based on the surface state of perovskite nanocrystals, the effects of passivation strategies with Lewis acid, Lewis base and surface coating on optical properties, and stability of CsPbX₃ perovskite nanocrystals are analyzed in detail combined with the domestic and abroad research work. Further optimization and improvement of the stability of CsPbX₃ are prospected.