The 2020 Meiyu season (June-July) witnessed eleven periodical rainstorm events in the middle and lower reaches of the Yangtze River (MLYR), strongly influenced by 10-20-day sub-seasonal interactions between Subtropical Jet (STJ) and Polar Front Jet (PFJ). The combinations of STJ and PFJ phases determined the position and direction of Low-Level Jet (LLJ) streams, and can govern the heavy rainfall belts and the Coupling Upper-and Lower-level Jet (CULJ) streams . The results further revealed that STJ and PFJ exhibited significant 10-20-day oscillations in horizontal velocity anomalies andemerged four distinct phase configurations(strong-strong, weak-weak, strong-weak, weak-strong), resulting in five strongly anomalousjet events during the 2020 Meiyu season.Particularly, the opposite-phase combinations of STJ and PFJ produced either zonal-oriented or V-shaped STJ patterns over from East Asia to Northwest Pacific, and spatially continuous STJ promoted the LLJ's development, enhanced moisture transport and dynamic uplift in the MLYR region, and facilitated heavy precipitation.The PFJ modulated the STJ's position, intensity, shape, and direction through wave-current interactions, thereby affecting the location of heavy rainfall belts in East Asia. Hence, sub-seasonal coordinated variations in STJ and PFJ and the periodic CULJ occurrences could be responsible for the super heavy rainfall events during the 2020 Meiyu season.