Tissue optical clearing technique plays an important role in three-dimensional (3D) visualization of intact organs or rodent bodies. As a typical organic-solvent based clearing method, 3DISCO renders the turbid tissues transparent by the strategy of minimizing light scattering, and possesses the advantages of high transparency and substantial size reduction, which could facilitate imaging of large-volume tissues. However, for heme-rich tissues, such as spleen, liver, embryo and clinical biopsy samples, tissue transparency and image quality by 3DISCO are limited due to the strong absorption ability of hemes. To address this problem, we proposed an optimized clearing method by introducing decolorization to modify the original 3DISCO protocol. The results showed that the optimized protocol could enhance the transparency of the heme-rich tissues and facilitate high-resolution imaging inside these tissues combining with optical microscopies.