Abstract: Aiming at the relationship between the structure and surface properties of diamond nanowires, diamond nanowires models of different shapes and sizes were established through first-principles calculations, The dimensional stability of diamond is studied and adsorption of oxygen atoms on diamond.The results show that the (111) surface of diamond nanowires is reconstructed on the surface of 1 ~2 atomic layers, and only when the size reaches a certain level, it has structural stability.The nanowires have good adsorption as a whole, but the adsorption performance of different surfaces is very different, and the side adsorption of nanowires is greater than that of surface adsorption.This study provides an important theoretical reference for the application of nanodiamond in biomaterials.