Abstract: Based on high-resolution multisource observational data, this study analyzed the topographic effects of the Taihang Mountains on the intensity, centers, and convective development characteristics of the “23·7” extreme precipitation event that struck North China. This long-lasting, widely impacting extreme precipitation event, marked by high intensity, was primarily caused by the northward movement of the remnant circulation of Super Typhoon Doksuri, with maximum cumulative precipitation reaching 1003.4 mm. Notably, the area of extreme rainfall and the record-breaking daily precipitation was concentrated on the upwind slope on the eastern side of the Taihang Mountains. The peak cumulative precipitation occurred at the altitude of approximately 400 m, and areas with accumulated precipitation above 600 mm were located within the inner corners of open-valley terrain composed of mesoscale mountains on the eastern slopes. The northern continental high, the Western Pacific Subtropical High, and the topography of the Taihang Mountains and Shanxi Plateau collectively influenced the slow movement of the typhoon’s residual vortex of Doksuri beginning July 29. The Beijing–Tianjin–Hebei region was dominated by convergence induced by the inverted trough on the northern side of the vortex and the topographical blocking effect, forming synoptic uplifting. A low-level easterly jet formed between the typhoon residual vortex and the high-pressure barrier, driving water vapor flux from the boundary layer over the plain up to the slopes of the Taihang Mountains. The convergence center of water vapor flux and subsequent upward movement occurred near 950–925 hPa on the mid-slope, fostering the precipitation peak in that region. The fine terrain of the Taihang Mountains had a significant impact on the occurrence and development of the Mesoscale Convective System (MCS). On the night of July 29, the MCS approaching the upwind slope was significantly enhanced. Under a background of northeast winds in front of the mountain, a convergence center formed on the inner side of the mesoscale trumpet-shaped terrain, producing sustained heavy precipitation. Boundary organization by the cold pool along the eastern edge of the MCS triggered new convection, leading to short-term rainstorms over the piedmont plains. On the night of July 30, another meso-β scale linear MCS developed locally under the influence of a southerly boundary jet and topographic vortex circulation. This system resulted in extreme rainfall intensity exceeding 100 mm h^-1. This study advances the scientific understanding of the mechanisms driving extreme precipitation in North China and helps to provide a reference for future forecasting decisions.