The invention provides a method for deparaffinizing a formalin-fixed paraffin-embedded tissue, including: providing a formalin-fixed paraffin-embedded tissue sample; mixing the formalin-fixed paraffin-embedded tissue sample with an organic solvent and water or with an organic solvent and an aqueous solution to form a mixture, wherein a density of the organic solvent is less than that of the water or the aqueous solution, and the organic solvent is immiscible with the water or the aqueous solution; and separating the mixture into an organic solution layer and an aqueous solution layer, wherein a paraffin dissolved from the formalin-fixed paraffin-embedded tissue sample is in the organic solution layer and a deparaffinized tissue from the formalin-fixed paraffin-embedded tissue sample is in the aqueous solution layer and/or an interlayer between the organic solution layer and the aqueous solution layer.