A novel multibranched nonlinear dye，4, 4´, 4´´-tris(9-carbazyl-trans-styryl) triphenylamine (TCSTPA)，has been designed and synthesized aimed at two-photon absorption applications. Two-photon absorption cross section of the multibranched dye was obtained as high as 2.35×10-47cm4s photon-1molecule-1pumped with femtosecond laser beam at 800 nm. One-photon and two-photon absorption optical properties were demonstrated in solutions. Three-dimensional (3D) optical data storage experiments were carried out by two-photon photobleaching in the multibranched-dye doped polymethylmethacryate (PMMA) with a 3D data storage density of approximate 14 Gbits/cm3. Research on the two-photon photobleaching ability shows the novel two-photon absorption dye with multibranched molecular motif has higher photosensitivity than traditional linear two-photon absorption dyes do.