The field-aligned anisotropy of the solar wind turbulence, which is quantified by the ratio of the parallel to the perpendicular correlation (and Taylor) length scales, is determined by simultaneous two-point correlation measurements during the time period 2001–2017. Our results show that the correlation scale along the magnetic field is the largest, and the correlation scale in the field-perpendicular directions is the smallest, at both solar maximum and solar minimum. However, the Taylor scale reveals inconsistent results for different stages of the solar cycles. During the years 2001–2004, the Taylor scales are slightly larger in the field-parallel directions, while during the years 2004–2017, the Taylor scales are larger in the field-perpendicular directions. The correlation coefficient between the sunspot number and the anisotropy ratio is employed to describe the effects of solar activity on the anisotropy of solar wind turbulence. The results show that the correlation coefficient regarding the Taylor scale anisotropy (0.65) is larger than that regarding the correlation scale anisotropy (0.43), which indicates that the Taylor scale anisotropy is more sensitive to the solar activity. The Taylor scale and the correlation scale are used to calculate the effective magnetic Reynolds number, which is found to be systematically larger in the field-parallel directions than in the field-perpendicular directions. The correlation coefficient between the sunspot number and the magnetic Reynolds number anisotropy ratio is −0.75. Our results will be meaningful for understanding the solar wind turbulence anisotropy and its long-term variability in the context of solar activity.

太阳风湍流的场对齐各向异性，由平行与垂直相关（和泰勒）长度尺度的比率量化，由 2001 年至 2017 年期间的同时两点相关测量确定。我们的结果表明，沿磁场的相关尺度最大，垂直场方向的相关尺度最小，无论是在太阳极大值还是太阳极小值处。然而，泰勒尺度揭示了太阳周期不同阶段的不一致结果。2001-2004年间，泰勒标度在场平行方向上稍大，而2004-2017年间，泰勒标度在场垂直方向上较大。太阳黑子数与各向异性比之间的相关系数被用来描述太阳活动对太阳风湍流各向异性的影响。结果表明，泰勒尺度各向异性的相关系数（0.65）大于相关尺度各向异性的相关系数（0.43），表明泰勒尺度各向异性对太阳活动更为敏感。泰勒标度和相关标度用于计算有效磁雷诺数，发现其在场平行方向系统地大于场垂直方向。太阳黑子数与磁雷诺数各向异性比之间的相关系数为-0.75。