Subaperture stitching interferometry in combination with null test can extend the lateral and vertical dynamic range of measurement, which is applicable to surface figure measurement for large aperture and high-departure aspheres. By employing a pair of counter-rotating Zernike phase plates as near-null optics, variable aberration is generated to balance most of the aberration for subapertures at different locations on various aspheric surfaces. The residual aberration is hence reduced within the vertical dynamic measurement range of a standard interferometer. The subaperture aberration of two test aspheres is calculated to solve the phase function of the Zernike plates. Meanwhile, the four-step etching process and power carrier are introduced to double the efficiency of diffraction and isolate the disturbance orders of diffraction. Finally the flexibility of the near-null optics is well demonstrated by applying it to the convex hyperbolic secondary mirror of stratospheric observatory for the infrared astronomy (SOFIA) telescope and a concave asphere. All subaperture aberrations are successfully reduced by the near-null optics, which shows its good adaptability to surface shape.