The invention provides an organic dye as well as a preparation method and application thereof. The organic dye has a structure of a formula (I) or a formula (II). Phenanthreneocarbazole and electron-rich thiophene unit are cyclic, the molecular energy level is regulated by selecting proper substituent groups, and when the organic dye disclosed by the invention is applied to a dye-sensitized solar cell, the photoelectric conversion efficiency is greatly improved. Meanwhile, the preparation method provided by the invention is rich in raw material source and low in cost, and industrial production can be realized. The structural formula is as shown in the description.