Based on the broadband waveforms recorded by Yunnan and Tengchong Volcanic Digital Seismic Networks, the authors inversed the focal mechanism solutions of the main shock of Yingjiang MS 5.8 earthquake sequences and MS≥4.0 foreshocks and aftershocks in 2011 by using CAP method. Combined with stress field and tectonic settings comprehensively, the seismogenic dynamic background of Yingjiang MS 5.8 earthquake was under the double effects which were northeastward compression of India Plate to Eurasia Plate and northeastward subduction of Burma arc to Baoshan-Tengchong block. The Baoshan-Tengchong block moved horizontally along NE direction, which leaded to the left-lateral strike-slip motion of Dayingjiang Fault.