[Objective] Investigations on rainstorm and flood processes and soil and water conservation in Beijing-Tianjin-Hebei region from July 29 to August 1, 2023 (referried as “7·23”) were carried out， and the rainstorm and flood processes in small basins and soil erosion caused by rainstorm were analyzed, in order to provide scientific support for soil and water conservation decision-making. [Methods] Field survey methods were used, in which flood marks were measured and investigated at Huangmi xigou and the Liangjiazhuang donggou of Lincheng County, Xingtai City, Hebei Province. The flood peak discharge modulus was calculated to analyze the erosion damage caused by rainstorm floods to small watersheds. [Results] ① The rainfall lasted for a long time and was strong. The cumulative rainfall in the Liangjiazhuang donggou valley and the Huangmi xigou valley reached 1 008.5 mm and 613.6 mm, respectively. ② According to the flood mark survey, the peak discharge modulus of the Huangmi xigou and the Liangjiazhuang donggou watersheds were 10.80 m³/(s·km²) and 36.07 m³/(s·km²), respectively. Slope and soil and water conservation measures were the main factors affecting flood peak discharge. Larger slopes will increase flood peak discharge, and soil and water conservation measures could play an effective role in peak reduction. ③ The investigated small watersheds were located in the upper reaches of the river basin, which is the main runoff producing area of the rainstorm center and flood. The peak flood discharge modulus of the small watersheds was larger than that of the downstream hydrology station. ④ The erosion situation of the Liangjiazhuang donggou was more serious than that of the Huangmi xigou, mainly due to the following reasons: the area proportion of orchards, terraces, and check dams in the Huangmi xigou was larger than that of the Huangmi west ditch; the average slope of the Huangmi xigou was smaller than that of the Liangjiazhuang donggou; and the peak duration of rainfall at the Liangjiazhuang rain-measuring station was longer. [Conclusion] Optimized soil and water conservation measures can effectively reduce the occurrence of flood peak discharge and erosion phenomenon. The implementation of soil and water conservation measures is necessary and effective. The construction of terraces and terrace valleys must be further improved.