This study analyzed the "24·7" extremely heavy rainfall event in southern Shandong using conventional observations, ERA5 reanalysis, and GDAS trajectory tracking data. The main conclusions are as follows: (1) The orientation of the rain belt is determined by the spatial configuration of the convergence zones ahead of the 700?hPa LLJ, 850?hPa LLJ, and 925?hPa SLLJ. During the first two stages, the convergence zones at various levels were oriented east-west, resulting in an east-west oriented rain belt. In the third stage, the intrusion of cold air shifted the convergence zone to a north-south orientation, causing a corresponding shift in the rain belt. During the initial nocturnal intensification of the jets, the northern boundary of the 925?hPa wind speed ≥12?m·s?1 corresponded to the southern boundary of the precipitation, while the northern boundary of the 850?hPa wind speed ≥12?m·s?1 corresponded to the northern boundary in the first two stages. After the southward advance of cold air in the third stage, the southern precipitation boundary was still defined by the 925?hPa SLLJ, whereas the northern boundary coincided with the convergence zone between the tip of the 850?hPa LLJ and near the shear line. (2) The diurnal variation in precipitation intensity was primarily dominated by the convergence associated with the 850?hPa LLJ and the 925?hPa SLLJ, exhibiting synchronous characteristics with "nocturnal enhancement and afternoon weakening". The 700?hPa LLJ provided steady convergence and moisture transport. Correlation analysis indicates that the regional average precipitation rate was significantly positively correlated with the intensity of jets at all levels, while the regional maximum precipitation rate was most closely related to the intensities of the 850?hPa LLJ and the 925?hPa SLLJ. (3) Moisture transport exhibited diurnal variations closely linked to the activity of the 850?hPa LLJ and 925?hPa SLLJ, with the diurnal variation in water vapor flux intensity at 850?hPa and 925?hPa aligning well with the evolution of precipitation intensity. The water vapor flux at 700?hPa remained consistently positive, providing stable moisture support for the maintenance of the torrential rain. (4) The moisture sources showed significant stage-dependent differences. In the first two stages, moisture was primarily sourced from the South China Sea and the Bay of Bengal, transported to southern Shandong by low-level jets for convergence. In the third stage, the southward intrusion of cold air brought a northern air mass, which had been moisturized over the Bohai Sea. This air mass converged with the warm, moist air from the South China Sea over southern Shandong, forming a "north-south moisture convergence" pattern. This significantly enhanced the intensity of moisture convergence and was a key condition for the precipitation to reach its peak during the third stage.