A three-dimension numerical model for the filling system of Baima Junction with water-saving lock is established to investigate hydraulic characteristics and mooring force with the normal operation scheme.The results show that the filling time is extended by 6.7% via a schedule of advanced valve opening of the next basin as compared to the same lock without basins.Furthermore,the first and second peaks of the flow rate among three peaks decrease by 30.98% and 31.6% respectively,while the third one increases by 15.16%.In addition,the longitudinal maximum mooring force and transverse maximum mooring force decrease by 36.25% and 44.18% respectively.The parameters of the hydraulic characteristics meet the specifications and design requirements.