Colloidal lead halide Perovskite nanocrystals (PNCs) have excellent optical properties that endow the PNCs with great application advantages in the display field. However, the ionic surface structure makes PNCs easy to degrade in light, heat, and air, which restricts their application. Here we report ligand-induced growth of crystalline ZnO on CsPbX3 (X = Br, I) PNCs for LED application based on the design of PNCs with carboxylate ligand capping. ZnO was grown on the surface of PNCs through in situ organometallic reactions, and a series of Type-II PNC/ZnO heteronanocrystals (PZNCs) were prepared. Crystalline ZnO effectively passivates the surface of colloidal PNCs and significantly improves their stability under various environmental conditions. White light-emitting diodes were fabricated with green- and red-emission PZNCs that achieved no obvious decay for long-time operation in air.