Based on the daily gridded precipitation dataset (CN05.1), NCEP/NCAR reanalysis data, and the Hadley Central Sea Surface Temperature Dataset (HadISST), linear regression and wavelet spectrum analysis, as well as the Linear Baroclinic Model (LBM), were employed to examine the temporal and spatial variability of summer precipitation in North China and its relationship with the Asian-Pacific Oscillation (APO) from 1961-2020. The results reveal that summer precipitation in North China exhibits a spatial pattern with higher amounts in the southeast and lesser amounts in the northwest, along with notable interannual variability. The APO modulates summer precipitation by altering the East Asian atmospheric circulation. More Specifically, intensified APO correlates with a stronger South Asian High, a more robust westward extension of the western Pacific subtropical high towards the north, and an enhancement of low pressure across the Asian continent, thereby intensifying East Asian and South Asian summer monsoons. This leads to enhanced moisture transport towards North China, fostering convergence and ultimately higher summer precipitation, and vice versa. Furthermore, the APO also modifies the SST gradient between the eastern and western Pacific regions via the wind fields, inducing an ENSO-like SST anomaly in the Pacific Ocean. This anomaly, in turn, impacts the Walker circulation and indirectly modulates summer precipitation in North China. Numerical simulations employing the LBM model further validate that anomalous heat sources over the Tibetan Plateau elicit a response in the upper tropospheric geopotential height, which fosters APO development and consequently the South Asian High. Simultaneously, the middle and lower troposphere exhibit an anomalous cyclonic circulation, bolstering the East Asian and South Asian summer monsoons, thereby enhancing water vapor transport towards North China and enhancing precipitation during summer.