To improve the precision strike ability of air force and to perfect the air-to-ground precision strike operational theory, based on lucubrating the precision strike operational theory and the air-to-ground precision strike characteristics, the connotation, physical constitution and key technology of air-to-ground precision strike system are analyzed. Air-to-ground precision strike system is the organic combination of information technology, precision strike weapon and artificial intelligent platform for war fighting. Reconnaissance monitoring platform, command and control system, data link system, weapon launch platform and guided weapon system are the subsystems. Ensemble technology for information operations system, battlefield information processing technology, information application technology for system operations and precision-guided ammunition key technology are the key technology to construct air-to-ground precision strike system. The conclusion is helpful to perfect the aeronautical ammunition weapon system.