The invention provides superfine deep yellow surface oxygen-enriched state nano titanium oxide powder for efficiently treating rhodamine B in printing and dyeing wastewater and a preparation method ofthe surface oxygen-enriched state titanium oxide powder. The yellow nano titanium oxide is formed by a two-step method for combining ultraviolet pretreatment and H2O2 after-treatment by adopting an aqueous solution method under normal temperature and normal pressure. The preparation process of the powder comprises the following steps: synthesizing light yellow nano titanium oxide suspension underultraviolet irradiation; and adding a proper amount of H2O2 aqueous solution, and drying, thereby obtaining the superfine deep yellow surface oxygen-enriched state nano titanium oxide powder. The method has the advantages of being simple and convenient in process, cheap in raw materials, energy-saving and environment-friendly. The obtained nano powder is high in photocatalytic activity of simulated sunlight and ultraviolet light and can be applied to the field of environmental protection of treatment of high-concentration dyes in industrial printing and dyeing wastewater.