从波像差的幂级数和圆泽尼克多项式展开理论入手，介绍了圆泽尼克多项式和赛德尔多项式之间的联系，理论上分析了圆泽尼克多项式在环域的相关性，着重讨论了以中心遮拦干涉图的圆泽尼克多项式拟合系数计算赛德尔像差系数的影响。对理论分析进行了实验验证，其结果与理论分析具有良好的一致性，并提出了一种简单直观的误差容限设定方法。研究表明，随着遮拦比的增加，赛德尔系数误差增加，其变化规律和被测元件的像差类型和大小有关。当遮拦比达到某一特定的阈值时，误差曲线将产生较大的变化，为了获得较准确的赛德尔系数，圆泽尼克拟合时应选择适当的阶数；当遮拦比继续增加时，为了计算出准确的赛德尔系数，拟合时应选择环泽尼克多项式。此外，遮拦比对赛德尔系数中畸变、像散的影响较弱，对彗差、场曲、球差的影响较强。

Based on the power-series' and Zernike circle polynomials' decomposition theory of wavefront aberration, the relationship between Zernike circle polynomials and Seidel polynomials is illuminated. The correlation Zernike circle polynomials on the annular domain is analyzed theoratically, and the effect of central obscuration interferograms fitted with Zernike circle polynomials on calculating Seidel aberrations is emphasized. The experimental results are consistent with the theortical analysis,and a simple and intuitionistic enactment method of error tolerance is provided. With the increase of obscuration ratio, it is found that the error of Seidel coefficients is increased, and its changing rule dependes on the aberration type and magnitude of the optical element under test. When the obscuration ratio reachs a certain threshold value, the error curves would greatly change. For achieving the accurate Seidel coefficients, the order number of the Zernike circle polynomial fitting should be selected apporiately, and the Zernike annular polynomials should be selected in a large obscuration-ratio case. Additionaly, the effect of the obscuration ratio on the tilt and astigmatism along Seidel aberrations is less than that on the coma, focus and spherical terms.