The invention discloses a titanium oxide phthalocyanine nanosheet and a preparing method thereof. The titanium oxide phthalocyanine nanosheet is uniform in size and is in a sheet shape, the diameter of the nanosheet ranges from 400 nm to 700 nm, and the thickness of the nanosheet ranges from 1 nm to 10 nm. According to the preparing method of the titanium oxide phthalocyanine nanosheet, an organic vapour deposition method is adopted, and the method comprises the following steps that firstly, titanium oxide phthalocyanine raw materials are put into a heating area of a furnace; secondly, under the carrier gas atmosphere, the titanium oxide phthalocyanine raw materials are heated to 410 DEG C to 440 DEG C, and titanium oxide phthalocyanine sublimates; thirdly, through carrier gas, the sublimating titanium oxide phthalocyanine is guided to deviate from the heating area and reach the growth area, and the temperature of the growth area is lower than the temperature of the heating area; and fourthly, in the growth area, the titanium oxide phthalocyanine nanosheet is obtained. The titanium oxide phthalocyanine nanosheet is in a new morphology, the property is excellent, operation is easy, the cost is low, pollutions are avoided, and a large number of nanosheets can be prepared.