The invention discloses a method for preparing black tea. The method includes the following steps that first, fresh leaves are picked, time from fresh leaf picking to fresh leaf spread-drying does notexceed 8 hours; second, the fresh leaves are spread-dried, specifically, the fresh leaf spread-drying thickness is 2-3 centimeters, and the fresh leaves are blown for 4-6 hours by natural wind at 4 meters / seconds; third, withering is conducted, specifically, the fresh leaves are blown for 4-6 hours by natural wind at 8 meters / seconds or above, and every one hour, tea green in a withering trough is ploughed in green for one time; fourth, rolling is conducted, specifically, the pressure of a barrel cover is adjusted according to a principle of light, heavy, light, heavy and light, and completedwithin 2 hours, and then the tea leaves are deblocked by a deblocking machine; fifth, fermentation is conducted, specifically, the deblocked tea leaves are put into a high-temperature and high-humidity fermentation room to be fermented within 2 hours, and the cumulative fermentation degree reaches 80-85%; and sixth, bake-drying is conducted, specifically, bake-drying includes the three steps of initial baking, full baking and re-baking, the process from beginning of fresh leaf picking to completing of initial baking and full baking is completed within 24-30 hours, and the black tea with excellent color, aroma, taste, shape and rhyme is prepared finally.