Abstract: The vertical structure and evolution mechanisms of the low-level vortices observed during two heavy precipitation events in North China during July 19–21, 2016 (Case 1) and July 11–13, 2021 (Case 2) were comparatively analyzed using conventional ground observations and ECMWF Reanalysis v5 (ERA5) high-resolution reanalysis data. The results indicate that both vortex systems originated under a similar large-scale circulation background characterized by low pressure to the west and high pressure to the east. The upper-level jet stream in Case 1 was significantly stronger than in Case 2, presenting the obvious difference between their large-scale circulation conditions. The two vortices exhibited distinct vertical structures. In Case 1, the low-level vortex developed deeply in the vertical direction, featuring two positive vorticity centers in the upper (300 hPa) and lower (850 hPa) layers. As the low-level vortex moved, the positive vorticity center in the lower layer gradually weakened, while that in the upper layer strengthened. This vertical coupling produced a temperature distribution that was warm at the top and cold at the bottom. A weak warm-core structure was observed at 400 hPa above a cold air mass, with dry and cold air appearing on the western side of the vortex’s central axis. In contrast, the low-level vorticity development in Case 2 was relatively shallow, with only one positive vorticity center consistently located at 850 hPa. The middle troposphere exhibited a pronounced warm-core structure between 700 and 300 hPa, situated above a cold core near the surface. The development of both low-level vortex systems was related to the downward transmission of upper-level potential vorticity (PV) and the transport of warm, moist air at lower levels. However, in Case 1, the intrusion of dry, cold air resulted in evident frontogenesis was observed in both upper and lower levels, with convective instability through the mid-to-lower atmospheric levels, which favored upward motion and enhanced positive vorticity. In Case 2, warm advection dominated throughout the troposphere, and the centers of PV and warm advection were both located below 850 hPa, nearly overlapping. This overlap led to strong upward motion and further development of the low-level vortex. The vorticity budget analysis showed that the total vorticity budget on the northern and eastern sides of the vortex centers was positive during various evolution stages of both vortices, indicating a tendency for the systems to move eastward and northward. During the development stages of both North China vortices, the horizontal divergence and tilting terms played key positive roles in promoting lower-level vorticity growth. The advection and divergence terms also contributed significantly and positively during the strengthening and weakening stages. A key difference between the two cases was that, in Case 1, the vertical transport term contributed positively during the strengthening and weakening stages—Particularly near the vortex center and its eastern side, whereas in Case 2, the vertical transport term remained negative throughout the entire evolution process.