A new type of nozzle-dispersion devices was developed to improve the performance characteristics of impact sprinklers under low pressure. Experiments were conducted under standard and non-standard conditions of dispersion-nozzle devices and working pressures, and then compared with the commercial LP R33 sprinkler. The main objective were to (1) study the optimal combination of the dispersion and nozzle devices to improve the hydraulic performance of the impact sprinkler under low pressure conditions; (2) evaluate the effect of sprinkler rotation with the optimal combination of nozzle and water dispersion device on water distribution uniformity; (3) analyze the jet characteristics of the optimal sprinkler, and establish an empirical spray range formula based on the dispersion angle (¿) and nozzle diameter (D2) for the optimal impact sprinkler; (4) To analyze the jet-breaking characteristics of the original and modified impact sprinklers, and find out why the hydraulic performance of new sprinkler is better through the jet breakup analysis; (5) conduct a comparative analysis of the hydraulic performance of the optimal impact sprinkler and the commercial LP R33 from Nelson.