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The submersible axial-flow pump system has been more widely applied in pumping projects. Usually the existing submersible pumps used for bi-directional pumping stations are the reversible pumps, the forward and reverse pumping of which is less efficient. The flow characteristics of a new bi-directional submersible pump system combined with the submersible pumps and two-way passages together were explored. By CFX software the full-flow numerical simulation of the system was made and the system flow field was obtained. Also the system hydraulic performance was predicted. The flow characteristics of suction passage with different measures were analyzed. The velocity distribution uniformity at outlet of suction passage showed the elliptical-type flow guide cone of the passage worked the best to prevent harmful vortex, which guaranteed the flow conditions of pump operation. Using specially designed discharge-chamber with unilateral angle of 18°, the flow separation was effectively inhibited, the hydraulic losses were reduced which ensured the overall efficiency of pump systems at high level. A model test was conducted in the high-precision test-bed of hydraulic machinery. The test results showed that under the pump head of 3.11m, flow rate of 256L/s, the pump system efficiency reached 71.9%, which was above the forward or backward pumping efficiency of reversible pump system by 7 and 13 percentage points, respectively. It was evident that the vertical submerged pump system with two-way passage was suitable for bi-directional pumping station. Experimental results and predicted model performance results were consistent in high efficiency area, and the numerical calculations were well verified.