The unsteady flows adjustment process of the Jinsha River and the Minjiang River are more complicated,and a new unsteady flow to the downstream propagation in Yibin section is formed after the confluence.According to the recent data,the paper analyzed unsteady flow characteristics and convergence effect of the Jinsha River and the Minjiang River.The results show that the unsteady flow characteristics of Yibin section is accordance with the unsteady flow characteristics of Xiangjiaba Hydropower Station;the unsteady flow in the Minjiang River has no typical process;there is a linear relationship of water level amplitude between Yibin section and the Jinsha River and the Minjiang River.Typical process of unsteady flow in Yibin section is a discharge wave which has about 1.7 m rising water level and about 1 m initial water level.Its propagation velocity in the downstream is basically consistent,and the attenuation amplitude decreases with the increase of distance.