Abstract: Taking the large-type tubular pump of Huai’an 3 Station of East Route Project of South to North Water Diversion as study background, the rear guide vane model was established and the hydraulic characteristics of tubular pump with and without rear guide vane were compared and analyzed through numerical simulation. On this basis, the further study on the influences of the rear guide vane number and installation position on the hydraulic characteristics was conducted. The study result showed that for the design work condition, rear guide vane can reduce flow circulation, recover kinetic energy and improve the flow state in bulb section and outlet passage, especially for medium and small discharge, increasing the efficiency of 5%. For the large-type tubular pump with 3 runners, when the guide vane number is 5, the hydraulic loss is the minimum, in addition, when the guide vane is installed in the expansion section, the hydraulic characteristics is the best. In general, the optimized rear guide vane can increase the pump efficiency by 0.5% under the design work condition.