Dynamic processes in weapon explosions, inertial confinement fusion and hypersonic flight occur under extreme high-pressure conditions. These transient, fast-evolving processes feature complex electronic structures and varied atomic environments, posing core challenges in related research. Using AI-augmented computational methods, we develop large-scale, first-principles-accurate simulation techniques to capture nanosecond–micrometer dynamics under dynamic loading. We derive thermodynamic properties and structural evolution of water and diamond in such regimes, supplying critical models and data for high-pressure physics. During ramp-compressed rapid freezing of water into ice VII, two key phenomena emerge: (1) Extreme ramp compression defers nucleation to pressures beyond classical nucleation theory forecasts, signifying a non-equilibrium nucleation path; (2) A thermally elevated nucleus paired with a high-mobility interfacial layer accelerates hydrogen bond rearrangement, boosting ice growth. Guided by these results, we put forward a universal scaling law to predict ice VII transition pressure under ramp compression, proving metastable water can be overdriven well past its stability limits. We further explore diamond phase transitions under shock loading, uncovering distinct orientation-dependent behaviors along [110] and [100] crystallographic directions. These drive the recrystallization of diamond and BC8 phases post shock-induced melting, respectively. Under uniaxial compression, the [110] plane’s unstable phonon vibrations raise dislocation susceptibility, promoting diamond nucleation. Linking atomistic dynamics to macroscopic phase transitions, our works deliver groundbreaking insights into dynamic-loading phase transitions within non-equilibrium dynamics.