Qingyuan second-line ship lock has a large plane scale and adopts a new type of energy dissipater with a combination of sill and beam. In order to understand the hydraulic characteristics when ship lock filling and discharging，berthing conditions and the interaction between double line ship locks，propose solutions to ensure the safe and efficient operation of locks，the hydraulic prototype observation and the full-scale ship test were carried out，and the hydraulic characteristics and other operation parameters of Qingyuan second-line lock were observed in detail，and various indexes were analyzed. The test results show that under the existing operation mode，the gate and the valve operate well，and all hydraulic indexes meet the design requirements of the specifications. However，due to the side-by-side arrangement of the first- and second-line ship locks on the same bank，the completion of the second-line lock leads to the change of the boundary conditions of the first-line lock. The upstream piers of the first-line lock are close to the inlet of the second-line ship lock. During the second-line lock filling，it will have a certain impact on the flow conditions of the berthing section of the first-line lock.Therefore，the joint dispatching of the first- and second-line locks should be strengthened.