The invention provides a method for refining J acid by using a multi-functional integrated device, which comprises alkaline water dissolution, salting out, filtering, washing, clear water dissolution integrated process and decoloration, filtering, washing integrated process and the acidification, filtering, washing, and drying integrated process, the alkaline water dissolution, salting out, filtering, washing, and clear water dissolution integrated processes are completed in a first multi-functional device integrating filtering, washing and drying into a whole and decoloration, filtering, washing integrated processes are completed in a second multi-functional device integrating filtering, washing and drying into the whole, and the acidification, filtering, washing, drying integrated processes are completed in a third multi-functional device integrating filtering, washing and drying into the whole. The method has the advantages of a small number of devices, small occupied area, high degree of automation, low loss of raw materials, easy realization of large-scale continuous operation and the like, and can be widely applied in dye production, organic chemical industry and other fields.