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本文由区域台网地震波资料，反演得到１９７６年云南龙陵地震群６０２个中小地震的震源机制解。文中对机制解的各参数进行了分析和系统聚类。结果表明：小震机制解的优势取向和主要类型与序列中的大地震震源机制一致。反演得到震源区应力场方向为：最大压应力主轴方位１９５°、仰角５°；中等压应力主轴方位３１４°、仰角７９°；最小压应力主轴方位１０４°、仰角１０°。这与其它资料给出的结果相符。虽然区域应力场的平均方向比较稳定，但震区仍受到震源区应力场调整作用的影响，因而龙陵震群的走滑型的小震机制表现出一定程度的离散性，并且正倾滑动和逆倾滑动类型的小震机制独立存在。小震机制解节面走向相对均匀地散布在各个角域，成为该序列小震机制的一大特点，分析认为这和震源处＂准均质＂的介质条件有关。
In this paper, focal mechanism solutions of 602 small-medium earthquakes in the 1976 Longling earthquake in Yunnan Province are obtained by seismic data from the regional network. In this paper, the parameters of mechanism solution are analyzed and clustered systematically. The results show that the dominant orientations and main types of solutions for the small earthquake mechanism are consistent with the focal mechanisms of large earthquakes in the sequence. The direction of the stress field in the source region is obtained by inversion: the maximum compressive stress is 195 ° in azimuth and 5 ° in elevation; the azimuth of medium compressive stress is 314 ° and the elevation is 79 °; the minimum compressive stress is in azimuth of 104 ° and elevation of 10 °. This is consistent with the results from other sources. Although the average direction of the regional stress field is relatively stable, the earthquake zone is still affected by the adjustment of the stress field in the source region. Therefore, the strike-slip system of small earthquakes in the Longling earthquake swarm shows a certain degree of dispersion, Anti-dumping sliding type of small earthquake mechanism exists independently. The small-scale mechanism solution nodal plane spreads relatively evenly in all angular domains and becomes a major characteristic of the small earthquake mechanism of this sequence. It is considered that this is related to the medium condition of “quasi-homogeneous” source.