In this paper, the authors calculate and map the patterns of Coulomb stress changes induced by a major earthquake sequence of 4 events M≥7 on the Xiaojiang-Zemuhe fault zone in 1733 to 1850, and analyze the effects of the static stress triggering induced by the individual preceding events to the following events. The results show that, in the sequence of major earthquakes, every following event occurred in an area where Coulomb stress had been remarkably increased by the preceding event(s). Therefore, the authors believe that mechanically significant interactions exist among the different segments of the Xiaojiang fault zone, as well as between the fault zone and the Zemuhe fault zone.