The invention discloses a method for preparing flower-sweet-aroma congou black tea from tea in summer and autumn. The method comprises the following steps of performing light supplementary withering on fresh tea leaves, performing making of green leaves, performing rolling, performing fermentation, performing drying and performing aroma-increasing treatment, wherein the fresh tea leaves are the tea in summer and autumn with one bud and two leaves or one bud and three leaves, and the light supplementary withering is performed by a method of combining yellow light withering with blue light withering; in the process of making of green leaves, the rotating speed of a machine for rocking of green leaves is 20-25rpm, and the process of making of green leaves is performed in three time gaps; in the fermentation process, fermentation is performed at 28-30 DEG C until the congou black tea has flower sweet aroma and does not have green grass smell; and the drying process comprises three steps ofperforming primary baking, performing rolling-frying and performing sufficient drying. According to the method disclosed by the invention, the defects existing in the prior art can be overcome, the flower-sweet-aroma congou black tea being tight and bent in shape strips, rich and durable in flower sweet aroma, red and bright in soup color, and mellow and brisk in taste is obtained. The technological process is simple, the equipment requirements are low, the energy consumption is low, and the method has technological innovation value, and is high in actual significance.