The invention relates to a design method of a jet flow test pipeline system. The design method comprises the following steps of 1) obtaining required parameters of the system according to a test target; 2) calculating a relation curve of the nozzle diameter, the air compressor volume flow, the air storage tank volume, the air storage tank pressure and the air supply time of the system, determiningan air source parameter according to a curve group and a test measurement time requirement, and obtaining an exhaust noise sound power level; 3) calculating noises of valves with different calibers,determining the calibers of the valves, determining the pipe diameters of important control parameters of the pipeline, determining a diffusion section and a straight pipe section behind the valve inthe pipeline, determining parameters of a muffling section and the length of the pressure stabilizing section according to the gas source, the noise source intensity of the pipeline and the pipe diameter of the pressure stabilizing section, and determining parameters of a contraction section; and 4) determining the length of the front straight pipe section of the nozzle, the anechoic chamber parameter and the exhaust channel parameter according to the measurement frequency requirement and the measurement distance requirement. Compared with the prior art, the method has the advantages of reliability, accuracy, good applicability and accuracy and the like.