The calculations of total energy,energy band structure,electronic density of states and Mulliken population of LaNi5M(M=0,D,Al) were performed by adopting the method of total energy combined with ultra-soft Pseudopotential technology.The trend of electronic structure for LaNi5、LaNi5D and LaNi4Al,which was analyzed,the Al element is inclined to substitute for 3g-site Ni.The change rules of band structure and density of states were analyzed,and calculated the model by Reflex in Material studio,the theoretical results of Power Diffraction spectrum accord well with that of the experiments spectrum.