The invention discloses a method for preparing a prebaked anode by utilizing anode slime, and belongs to the technical field of prebaked anode preparation. The present invention collects anode slime, adds sulfuric acid for immersion, mixes and stirs to collect sediment for later use, and filters to obtain a filtrate, adds citric acid to the filtrate, stirs and reacts, obtains turbid liquid through filtration, mixes with the spare sediment, kneads and presses After the green body is formed, it is kept warm in a calciner, and then the temperature is raised, and after calcined, it is immersed in water to cool to room temperature, and air-dried to obtain a prebaked anode. The beneficial effects of the present invention are: the preparation steps of the present invention are simple, the energy consumption of the obtained product is more than 30.2% lower than that of other products, no need for regular replacement, and the service period is long; the material is not easy to oxidize and fall off during use, and the electrolytic current efficiency is increased by 22-25% %.