Magnetostriction of TbyDy1-x(Fe1-xTx)2(T=Al,Mn) single crystals, prepared by the MCGS-3 CZ instrument, was investigated. The intrinsic magnetostrictive properties were derived by fitting method of X-ray diffraction patterns of polycrystal samples prepared by arc-melting method. The substitution of AL, Mn for Fe lowers the saturation field and magnetocrystalline anisotropic energy. The intrinsic magnetostriction, 111, decreases with increasing amount of Al or Mn. For Tb0.5Dy0.5(Fe0.9Mn0.1)2 single crystals,a large magnetostriction and high d33 can be obtained under the compressive stress of 1226 MPa.