The electronic structure of FeAl was determined by one cell state method and the curve of potential energy, lattice constant, cohesive energy, bulk elastic modulus, and the variation of linear thermal expansion coefficient with temperature were calculated. It was found that most of the theoretical values of these properties above are in good agreement with experimental ones. The relationship between electronic bonding and crystal structure/brittleness was discussed by using the calculated electronic structure. The electronic structure of FeAl was determined by one cell state method and the curve of potential energy, lattice constant, cohesive energy, bulk elastic modulus, and the variation of linear thermal expansion coefficient with temperature were calculated. It was found that most of the theoretical values ​​of these properties above are in good agreement with experimental ones. The relationship between electronic bonding and crystal structure / brittleness was discussed by using the calculated electronic structure.