Since the operation of Xiangjiaba hydropower station in Jinsha River，it brings great benefits to the society and economy，meanwhile the unsteady flow process brings disadvantageous effects to the passage of vessels in the channel from Yibin to Luzhou in the upper reaches of the Yangtze River. In order to increase the cargo capacity of more large and medium-sized ship and can be smoothly through the channel along the dangerous shoal，we use the optimization of one dimensional unsteady flow mathematical model to calculate Yibin to Luzhou channel along the discharge and water level process，analyze unsteady deep water resources space-time distribution in accordance with the verified calculation results，and obtain the along propagation time during the dry season of Yibin to Luzhou channel under unsteady flow，the best navigation time of Yibin and ship speed on dangerous shoal.