The invention discloses a hydraulic pressure test system and test method for a large-pipe-diameter conveying pipeline. The hydraulic pressure test system comprises a test pipeline, wherein one end ofthe test pipeline communicates with a water injection pipeline, the other end of the test pipeline communicates with a first exhaust pipeline, the joint of the test pipeline and the water injection pipeline and the joint of the test pipeline and the first exhaust pipeline are sealed by adopting blind plates, valves and pressure gauges are arranged on the water injection pipeline and the first exhaust pipeline, one end of the water injection pipeline is connected with a pressure test pump, a water source connecting pipe communicates between the pressure test pump and the pressure gauge on the water injection pipeline, a second exhaust pipeline communicates at the highest point of the test pipeline, and a drainage pipeline communicates at the lowest point of the test pipeline. According to the invention, by improving the structure and arrangement mode of the hydraulic pressure test system, the difficulty brought to a test due to the intensive pipeline pressure is overcome, and the problems of overlong test preparation time, overhigh pressure test experimental cost, inaccurate pressure test detection data and the like in the hydraulic pressure test are effectively solved.