Tungsten carbide (WC) is increasingly used in high-temperature power equipment. The brittleness and high density of WC limit its wider use. Metal atom doping is a method to improve the performance of WC. The generalized gradient based on the first principle is used as the approximate exchange correlation function. The elastic, electron and X-ray absorption characteristics of A0.25W0.75C (A is Ti, V, Cr, Mn, Co and Ni) were studied. According to the numerical analysis, the B/G value of Ti0.25W0.75c (B is the volume modulus, G is the shear modulus) is 1.869, the material is the modified ductile material, and the others are brittle materials. The brittleness of WC decreases with the doping of 25% V and Co atoms, and brittleness increases with the doping of 25% Cr, Mn and Ni atoms. After doping, the range of density of state decreases, the value of Fermi level increases, and the metallicity of the compounds increases. Among them, Mn0.25W0.75C has the strongest metallicity. The X-ray absorption spectrum shifts blue after doping, and there is an absorption band in a soft X-ray band. The strong absorption peaks of doping Cr, V, and Ti appears in the 15.74～22.25 nm band. The results are helpful to the experimental and application study of WC compounds with plasticity and low density.