There is a mega tectonic system in south Asia, which is called South Asia “Z” shaped tectonic system in Lee’s geomechanics theory. Its range mainly involves Qinghai Tibet, Yunnan, Myanmar and Indonesia. The present activity of the tectonic system is very prominent and controls many large earthquakes (M≥ 6 8 ) distribution, so it is a typical active tectonic system. Based on recent studying on active faults and earthquake geology, we analyzed in detail the present activity and large earthquake events since 1320 A.D. along the active tectonic system. The studying results show that the consistency aspects of kinematics and large earthquakes chain reaction or domino effect resulted from active fault interaction are all very obvious along different structure segments of the mega tectonic system. The interaction effect of large earthquakes is that the middle segment occurred immediately large earthquake events soon after (usually about few months or few years, and sometimes more than ten years) some large earthquakes occurred along the head of tail of the South Asia “Z” shaped mega tectonic system. But during the latest large earthquake cycle since 1997 A.D., the Sichuan Yunnan constituting the middle segment of the tectonic system, which is a typical active province of large historical earthquakes in west south China, appeared aseismic period of large earthquakes sustainable more than ten years after many large earthquakes occurred along the head and tail segment of the tectonic system. The long large earthquakes quiescence occurred in middle segment is obviously incompatible with the interaction effect of large earthquakes of the South Asia “Z” shaped tectonic system, and implies that there is very high large earthquake hazard in the near future at the middle structure segment. Based on the newest active faults studying on Sichuan Yunnan arc rotation shearing active tectonic system combining with three fundamental criterions of seismic hazard assessment, including elapsed time after large earthquake events, seismic gap and chain reaction or domino effect of large earthquake events, we suggest that there are 9 large earthquake high hazard areas or belts in the Sichuan Yunnan arc active tectonic system, including: Anninghe segment of the Xianshuihe Xiaojiang fault zone, Qiaojia segment of the Xianshuihe Xiaojiang fault zone, the southern section of the Xiaojiang fault of the Xianshuihe Xiaojiang fault zone, Heqing Songgui graben basin and the Chenghai Binchuan fault in rifting zone of the west north Yunnan, the seismic gaps along the Wanding fault and Nantinghe fault, the east south segment of the Lancang Jinghong fault zone, Yuanmou graben and Baoshan graben. The new seismic hazard assessment results are helpful to understand present large earthquake trend on the Shichuan Yunan active tectonic system of west south China.