The sinistral strike- slip Xianshuihe- Xiaojiang fault system is one of the largest boundary fault zones that accommodate the southeast extrusion of crustal masses from the southeastern Tibetan Plateau. The late Quaternary strike- slip rate of the Qiaojia fault, the northern segment of the Xiaojiang fault zone, is the key to understand the strain accommodation mode of the eastern boundary of the Sichuan- Yunnan Block. In this paper, high- resolution topographic data of the fault section at Honglu and Menggu along the Jinsha River Valley area are obtained, using Structure from Motion (SfM) and Terrestrial Laser Scanner (TLS) techniques. It is shown that the left- lateral displacements cutting across the upper parts of the T2 and T3 terraces are 120±5~128±1 m and 193±1~202±1 m, respectively. AMS- 14C dating of secondary carbonates from the T3, in combination with the previous dating results of similar terraces and correction by climate curves, reveals that the abandonment of T2 and T3 in the region occurred at ca. 8.5~11.2 ka BP and 18.6~21.4 ka BP in the post glacial period and at the end of the last maximum glaciation period, respectively. Accordingly, the average late Quaternary strike- slip rate of the Qiaojia fault is estimated at ca. 10~13 mm/a. The late Quaternary stike- slip rates of the other two segments of the Xiaojiang fault zone are further summarized in this study. It is shown that the fault zone generally maintained a high strike- slip rate of 10~15 mm/a from Qiaojia to the north of Yiliang. However, the strike- slip rate decreases step- by- step from Yiliang southward and rapidly decreases to nearly one tenth of the rates of the middle- north segment to the south of Jianshui. The step- by- step decrease along the south part of the fault zone suggests that the extrusion movement of Sichuan- Yunnan Block has changed from sinistral strike- slip shearing to concurring extension, rotation and thrusting in this region. Therefore, further quantitative constraining the strain partitioning along the boundary faults of the Sichuan- Yunnan block may provide deep insights into the accommodation mode of mass extrusion in the southeastern Tibetan Plateau.