Axial adjustment mechanism is applied in deep ultraviolet photolithography objective lens for aberration compensation. Since the surface accuracy of the optical element in the objective lens is rigorous, effect of the adjusting force on the surface figure of optical element in the axial adjustment mechanism cannot be ignored. Regularity between the adjusting force and the surface figure of the optical element is investigated aiming at an axial adjustment mechanism with monolithic configuration. Finite element method is adopted to analyze the relationship between the adjusting force and the root-mean-square (RMS) value, Code V standard Zernike coefficients for the surface figure evaluation of the optical element. Methods for reducing the effect of the adjusting force on the surface figure of optical element are further proposed, which is adjusting force isolation and adjusting force absorption. The calculation results show that the RMS value and the Zernike coefficients linearly change with the adjusting force, and the adjusting force does not cause the existing aberration to transform into other types of aberrations, nor lead to a new generation of aberration. After flexible structure is introduced and set between the optical element and the support mount of the axial adjustment mechanism, the variation amplitude of RMS value reduces from 187% to less than 8%, which indicates that the effect of the adjusting force on the surface figure of optical element is effectively controlled.