The invention discloses a method for breeding aphidius gifuensis within a short cycle. The method comprises the steps of: host plant cultivation, pest species breeding, and aphidius gifuensis large-scale breeding. A breeding cycle of the whole process is 29-40 days. Each dish of brassica chinensis can breed more than 12000 of aphidius gifuensis, a parasitism rate of the aphidius gifuensis is 95%, a formation rate of stiff aphids is 60%, and stiff aphids of the aphidius gifuensis in each dish can be used for controlling 10-15 mu of aphid-damaged farmland. Brassica chinensis of a vegetable variety is adopted as a host plant with high strong adaptability and fast growth; and the brassica chinensis a host plant variety with a shortest cultivation cycle in current breeding technology of sphidius gifuensis, thereby reducing a breeding cycle of the aphidius gifuensis, and improving breeding efficiency of the aphidius gifuensis. The method adopts a flotation breeding method for cultivating the host plant, is simple in process step and solves the problems such as high breeding energy consumption, a tedious technical process, poor activity of the aphidius gifuensis, and irregular formation of the stiff aphids of the aphidius gifuensis, and can increases a utilization rate of the aphidius gifuensis for wide application in agriculture and forestry industry, thereby enabling the aphidius gifuensis to have better feasibility of production, promotion, and application.