The variation characteristics of summer precipitation in Shandong and their relationship with atmospheric circulation are studied based on summer precipitation data of 123 national meteorological stations from 1961 to 2015 and NCEP reanalysis data from 1991 to 2015. The results indicate that when the summer precipitation in Shandong is more (less), Ural blocking high is weaker (stronger), the subtropical high is stronger (weaker), South Asia high is stronger (weaker), and an obvious wave train that resembles the Silk Road Pattern appears on the meridional wind field at 200 hPa. The downscaling prediction model is established utilizing the second generation of National Climate Center coupled ocean-atmosphere model to predict the future summer sea-level pressure from March, and the sign consistency of prediction by downscaling interpretation method and observation can reach 64%. The downscaling method has predictive ability for the ability of summer precipitation in Shandong. Further analysis shows that the simulation and prediction ability of the model on circulation factor of key region has significant influence on the skill of downscaling method.