Based on the daily gridded precipitation dataset (CN05.1), NCEP/NCAR reanalysis data and HadISST monthly data, the linear regression and wavelet analysis, as well as the linear baroclinic model (LBM), are employed to examine the spatial-temporal variability of the summer precipitation in North China from 1961 to 2020 and its relationship with Asian-Pacific Oscillation (APO). The results are as follows. (1) The summer precipitation in North China exhibits a spatial pattern of higher values in the southeast and lower values in the northwest, and there is notable interannual variability. (2) The APO modulates the summer precipitation in North China by altering the East Asian atmospheric circulation. More specifically, the intensified APO correlates with a stronger South Asia high, a stronger and northward western Pacific subtropical high and an enhancement of low pressure across the Asian continent, thereby intensifying the East Asian and South Asian summer monsoons. This leads to the enhanced transfer of water vapor towards North China, fostering convergence and ultimately higher summer precipitation in North China, and vice versa. (3) The APO also modifies the sea surface temperature (SST) gradient between the eastern and western Pacific regions via wind fields, inducing an ENSO (El Niño-Southern Oscillation)-like SST anomaly in the Pacific Ocean, which, in turn, impacts the Walker circulation and indirectly modulates the summer precipitation in North China. (4) The numerical simulations employing the LBM further validate that the anomalous heat sources over the Qinghai-Tibet Plateau elicit a response in the upper tropospheric geopotential height, which fosters APO development and consequently a stronger South Asia high. Simultaneously, the middle and lower troposphere exhibits an anomalous cyclonic circulation, which bolsters the East Asian and South Asian summer monsoons, thereby enhancing the transfer of water vapor towards North China and the summer precipitation there.