The stability of perovskite nanocrystals (NCs) is greatly limited due to the highly dynamic binding of ligands, which hinders the development of optoelectronic devices. It is well known that surface ligands play a critical role in stability. The establishment of a strong interaction between the ligand anchoring group and the NCs surface is beneficial to passivate surface defects and improve stability. Hence, the importance of developing new ligand strategies is evident. In this work, we employed a new ligand strategy to prepare CsPbBr₃ NCs via a facile room temperature assisted precipitation (LARP) method with N1.N2-Didodecyl-N1.N1.N2.N2-tetramethylethane-1.2- diaminium bromide (DTDB) as the sole ligand and additional Br resource. Compared to other new ligands with one coordinating group, this class of bidentate ligand can be tightly anchored to the surface of NCs with double N⁺ sites. The DTDB-CsPbBr₃ NCs exhibit high PLQY of 92.3% and superior colloidal stability. Besides, it exhibits superior purification endurance for 49% of the initial PLQY is maintained after ten purification cycles. Compared to DTAB-CsPbBr₃, it displays improved colloidal stability to light, heat and water for the strong interactions between CsPbBr₃ NCs and DTDB ligand. We believe that the DTDB ligand is an ideal alternative to commonly used ligands.