中文摘要：

对于太阳活动22年周期的成因机制长期存在着争论．本文借助于行星会合指数以及开普勒第三定律，对太阳绕太阳系质心运动周期进行了分析计算．结果发现，太阳绕太阳系质心运动存在22．1826年显著周期，这与太阳磁场变化的22．20年周期相吻合．并从太阳系角动量守恒的角度解释了两者之间的成因联系：在太阳绕太阳系质心运动的准22年周期中，太阳系质心与太阳质心逐步接近而后逐步分离．当两个质心之间的距离接近零的时候，太阳轨道角动量与自转角动量叠加，会导致太阳自转角速度的加快；当两个质心之间的距离逐渐远离的时候，则导致太阳自转角速度的减慢．这可能是引发太阳活动和太阳磁场变化的原因．这一新认识为太阳活动准22年周期成因机制的解释提供了新的线索和依据．

英文摘要：

The mechanism of the 22-year cycle solar activities remains a focus of debate. We calculated and analyzed the periods of the Sun＇s revolution round the solar system mass center, based on the planets-conjunction index and the Kepler′s laws of planetary motion. It is found that the solar revolution round the solar mass center has an obvious cycle of 22. 1826 years, coinciding well with the solar magnetic change cycle of 22. 20 years. The mechanism and relationship between them can be explained in terms of the law of conservation of angular momentum in the solar system. The distance of the solar system mass center from the Sun＇s mass center varies with the planets revolution round the Sun. During a 22. 1826 years cycle, the distance decreases in a half time and increases in another half time. The rotational angular velocity of the Sun may increase with the decreasing of the distance, and reach its maximum when the distance betweenthe two mass centers approaches to zero, because the angular momentum of the Sunts revolution round the solar mass center would transform into that of the Sunrs rotation. This interpretation is supported by the observation for the 22-year cycle variation of the rotational angular velocity of the Sun. This study supplies a new solution for deeper understanding the dynamic mechanism of the 22-years cycle of the solar activities.