The migration, transformation and accumulation in the environment of heavy metal elements in coal fly ash are the barriers to the comprehensive utilization of coal fly ash. To clarify the occurrence state of heavy metal elements in coal fly ash and to explore an efficient removal method, it is the key to solve the large-scale utilization of coal fly ash. The improved BCR continuous extraction method found that the water soluble and acid exchangeable states of heavy metal element arsenic in fly ash accounted for a high proportion, which proved that heavy metal arsenic easily migrated in the environment and affected the surrounding environment. Based on the occurrence characteristics of heavy metal arsenic in coal fly ash, a new method for removing heavy metal element arsenic by sulfuric acid was established. The effects of sulfuric acid concentration, reaction temperature and reaction time on the removal rate of heavy metal arsenic were investigated. The results showed that the removal rate of arsenic increased with the increase of the concentration of sulfuric acid solution, decreased with the increase of reaction temperature, and increased with the increase of reaction time. Considering the removal rate of heavy metal arsenic, the loss rate of constant elements in coal fly ash and the degree of damage of spherical particles, the optimum conditions for removing heavy metal arsenic from coal fly ash by one-step method of sulfuric acid determination were as follows: the sulfuric acid concentration of 2.0 mol/L, the reaction temperature of 20℃, and the reaction time of 60 min. At this time, the removal rate of heavy metal arsenic reached 75.21%.