Abstract: Micro-sprinkling hoses have been widely applied in water-saving irrigation equipment, due to their easy reliable installation, strong anti-clogging capability, and low cost. The performance of micro-sprinkling hoses can depend mainly on a set of orifices. Particularly, the water distribution of a single orifice can pose a significant impact on the spraying uniformity. Previous studies were focused on the spray characteristics of a single orifice on the surface with range, wet area, and width of the drying zone. But it was difficult to quantitatively analyze the spatial characteristics of water distribution. Therefore, it is necessary to accurately determine the water distribution of a single orifice in a micro-sprinkling hose. In this study, an indoor experiment was carried out for the water distribution of the micro-sprinkling hoses without the wind effect. 12 holes were set in the belt with a folded inner diameter of 54 mm, and a wall thickness of 0.5 mm. Specifically, the measured orifice area of the micro-sprinkling hose was 0.073-0.279 mm2, the orifice spacing was 47-52 mm, and the hole spacing was 47-52 mm. Among them, the indoor temperature was about 20℃, and the relative humidity was about 55%. A pressure regulator was selected for the fluctuated pressure of the micro-sprinkling hose caused by the municipal water supply. The length of the sample hose was 2 m in the test. The spraying angle varied from 40° to 90°, and the working pressures were 41.0, 69.0, and 103.0 kPa. The micro-sprinkling hose was laid flat on the spray side of rain gauges. The origin of the coordinate system was placed at the center of the single orifice, where the direction of flowing water in the micro-sprinkling hose was set x-axis, and the placement direction of rain gauges was set y-axis. The indoor test indicated that there was a unimodal or bimodal two-dimensional water distribution of a single orifice. Unimodal and bimodal distribution models were developed to fit the water distribution using the normal distribution probability density function. The results showed that the peak error was small between the fitting and experimental value, and the coefficient of determinations was greater than 0.80, indicating an excellent agreement with the experimental measurements. A systematic analysis was also made to explore the impacts of pressure, spraying angle, and orifice area on the coefficients in both unimodal and bimodal distribution models. Consequently, there was a little effect of pressure on the peak value of intensity distribution during water application, but the higher peak value and the range of irrigated area were found in the spraying direction of bimodal distribution. Furthermore, the irrigated area was reduced to intensify the application rate, as the spraying angle increased. Once the spraying angle reached a critical value, the peak value started to increase, particularly for the more concentrated distribution of irrigation intensity in the spraying direction. Therefore, the larger orifice areas resulted in the larger irrigated areas. The finding can provide an important reference for the design and optimization of micro-spray hoses for water-saving irrigation.