In consideration of the capturing alkali metal characteristics of high alkali coal ash,the phase change and element migration in high alkali coal were studied by experimental simulations when the reaction between high alkali coal and its own ash was sustaining. By virtue of the quantum chemistry theory, the physical and chemical properties of reactive coal mineral albite were calculated and analyzed in order to theoretically guide the control and improvement of practical coal combustion in industrial boilers. The results show that it is highly feasible to solve the fouling and slagging problems of high alkali coal combustion by making use of the good capturing effect of high alkali coal ash. The captured sodium is mainly deposited in coal ash minerals such as nepheline and albite, and its migration features are changeable with the variation of temperature condition. The mineral albite in coal ash has good reactive activity, and easily reacts with an electrophilic system. The highest occupied molecular orbital of albite is mainly contributed by the 2p orbital of oxygen atoms, and the length of Al-O bond in albite is longer, which primely results in the fracture and generation of chemical bonds.