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丽江７０级地震震区位于我国西南地区现代构造应力场空间分布的复杂地区，区域应力场主压应力优势方位为南南东。震区位于可能受到多种构造动力源作用的特定构造运动环境中。获得了主震和２２个ＭＬ≥４０级余震的震源机制Ｐ波初动解，分析表明，主震发震应力场为北３°东，与震区区域应力场主压应力优势方位有一个小角度的偏差。主震的发震应力不仅有水平应力的作用，同时还有显著的垂直应力的作用。在余震序列发展中震区呈现出应力场分布的复杂图象。地质资料表明，震区处在北西、北东和北北西———北北东向三条较大规模构造断裂所围限的三角形断块内。推测主震发生在北西向边界断裂与断块内近南北向断裂的交汇部位，并且自交汇点分别向此两断裂两侧破裂，形成震源的两次破裂过程。主震的破裂错动以正倾滑动为主，兼具左旋剪切错动分量。余震主要发生在三角形断块内，并且显示为多条规模不大的断裂活动的碎裂型破裂特征
The 7.07 earthquake in Lijiang is located in a complex area with the spatial distribution of modern tectonic stress field in southwest China. The predominant azimuthal stress azimuth of regional stress field is south-south east. The earthquake zone is located in a specific tectonic environment that may be affected by a variety of tectonic sources. The P wave initial motion of the focal mechanism of the main shock and 22 ML≥40 aftershocks was obtained. The analysis shows that the predominant seismic shock stress field is north 3 ° east and the dominant azimuth of the principal compressive stress field of the earthquake zone is A small angle of deviation. The seismic shock stress of the main shock not only has the effect of horizontal stress, but also has significant vertical stress. In the development of aftershock sequences, the earthquake zone presents a complex image of stress field distribution. Geological data show that the earthquake zone is located in the northwest, north east and north-north-north-north east of the three large-scale structural faults surrounded by triangular fault block. It is presumed that the main shock occurred at the junction of the northwestern boundary fault and the near-north-south fault in the fault block, and ruptured to both sides of the two faults respectively from the junction, forming two ruptures of the source. The rupture of the main shock dislocates mainly in the positive dip, and it has the components of the left-hand-shear fault. Aftershocks occur mainly within triangular fault blocks and show as a number of fragmented fractures of small-scale fault activity