High-efficiency extraction of Al from coal-series kaolinite and its kinetics by calcination and pressure acid leaching has been studied in detail. Calcination process promoted a phase transform from crystal kaolinite to amorphous compounds. Subsequently, Al occurred in the compounds was efficiently extracted by pressure acid leaching. At optimal conditions, the extraction rate of Al reaches 98.7%. Pressure leaching process of Al was successfully described by Avrami model, and mainly controlled by chemical reaction when apparent activation energy was 16.29 kJ/mol. The complex extraction process of Al in heated acid leaching (diffusion-reaction-diffusion) was transformed into a simple chemical reaction during pressure leaching so as to realize a high-efficiency extraction of Al from coal-series kaolinite. Display omitted •Pressure acid leaching realizes a high-efficiency extraction (98.7%) of Al from calcined coal-series kaolin.•Leaching kinetics of Al during pressure acid leaching is successfully described by Avrami model.•Pressure leaching of Al is mainly controlled by chemical reaction with apparent activation energy of 16.29 kJ/mol.