Irrigation performance in fields is an important factor for the yield and water use efficiency of crops. For the unreasonable field size in Hetao Irrigation District, the flow and performance change of irrigation water in fields were analyzed by irrigation experiments in different widths of fields in order to find proper technical factors of irrigation water in fields by model simulation and regression analysis. Results showed that the irrigation performance was poor with irrigation uniformity of only 59.78%~77.40% and 84.61%~87.02% when the width of fields was 18~23m. Although water storage efficiency was 100%, the irrigation performance was still poor. When the width of fields was reduced to be 10~15m, the irrigation efficiency was 70.20%~87.00% and irrigation uniformity was 86.77%~90.80%, which showed best irrigation performance. When the width of fields was reduced to be 5m, the irrigation performance was deteriorated. A single objective optimization model included irrigation efficiency and irrigation uniformity and storage efficiency combined with the field experiment data was constructed through the combination of model simulation, uniform experiment design and multiple regression analysis. Through using the single wide flow and irrigation time as decision variables and solving the model by bubble sort method, the optimal combination of technical components of border irrigation was obtained, and the appropriate width of the field was further determined based on the actual flow in the demonstration area. The results provided theoretical support for the water-saving transformation design, effective utilization of water resources and agricultural sustainable development in irrigated areas.