The present invention provides a manganese sulfate purification and crystallization method. The use amount and the type number of impurity removal agents used in the method of the present invention are small, a filtrate obtained after crystallization and filtration is distilled, recovered ethanol is used for circulating crystallization, a distilled liquid is used as a manganese slag leaching base solution again to be added into a reaction kettle, and sulfuric acid is added again for preparing a manganese sulfate solution by means of cyclic leaching. The process is simple and easy to implement, the additive amount is small, high-temperature crystallization is not needed, and process costs are greatly reduced.