Density functional theory with generalized gradient approximation (GGA) and local density approximation (LDA) approximation mechanical properties of GaAs1-xSbx of x function have been calculated from different pressure. The geometry adjusted structural parameters for GaAs1-xSbx under separate pressures and they have been listed. It was detected that lattice constant decreased by pressure increasing. Furthermore, pressure increasing led to an increase of parameter Shear modulus and Young modulus and a decrease of parameter Bulk modulus. The elastic constants fulfilled the customary mechanical stability conditions for the ternary intermingled crystals. The elastic modulus was gained. The adjusted elastic constants varied with various rates under increasing pressure.