根据惠更斯菲涅耳原理，推导得到多色完全空间相干光在杨氏双圆孔干涉远场的光谱分布表示式，并进行了详细的数值分析。结果表明，观察屏上与y轴成45°角的斜直线上光谱开关数目随双圆孔中心遮拦比的增大而减少，光谱开关间距趋于相等；而该斜直线上任一固定点处的光谱开关间距却随之不断缩小。分析计算还表明，在平行于双圆孔中心连线的x轴上的光谱分布与双圆孔中心遮拦比无关，光谱开关间距相等，改变圆孔半径大小可以控制x轴上的光谱开关数目。在与双圆孔中心连线垂直的y轴上，光谱分布与空间点的位置坐标、圆孔半径及双圆孔中心遮拦比均有关，随着中心遮拦比的增大，光谱开关间距趋于相等。

According to the Huygens-Fresnel principle in the paraxial domain, an expression for the spectrum of polychromatic spatially coherent light in Young′s double-circular-aperture interference experiment in the far field is derived, and detailed numerical calculations are performed. It is shown that the number of the spectral switches on the oblique straight line with the y axis angle of 45° in the viewing screen is decreased with the increase of the central obstruction ratio of double-circular-aperture, and the distances among spectral switches on the line tend to be equal. With the increase of the central obstruction ratio, the distances among spectral switches at a fixed point on the straight line are shrunk. It is also shown that the spectrum on the x axis parallel to the double-circular-aperture center connection line is independent of the central obstruction ratio, and the distances among spectral switches are equal, changing the radius of the double-circular-aperture can control the number of spectral switches on the x axis. The spectral shifts and spectral switches on the y axis perpendicular to the center connection line depend on the location coordinates of the spatial points, the radius of the circular apertures and the central obstruction ratio of double-circular-aperture. With the increase of the central obstruction ratio of double-circular-aperture, the distances among spectral switches tend to be equal.