The invention discloses an expanded floating feed for siniperca chuatsi and a preparation method thereof. A formula of the expanded floating feed for siniperca chuatsi, which is provided by the invention, contains the following substances: chicken powder, cassava starch, euphausia superba powder, rice protein powder, fish soluble protein, pea protein powder, cuttlefish powder, wheat gluten, fermented soybean meal, spray-dried animal blood cells, monocalcium phosphate, bentonite, phospholipid oil, fish oil, fish microelements, fish multivitamin, sodium humate, choline chloride, a mold inhibitor, a vitamin C additive, an antioxidant, inositol and carnitine. The expanded floating feed for siniperca chuatsi, which is provided by the invention, is capable of improving the digestive ability of siniperca chuatsi, obviously promoting weight gain of siniperca chuatsi, increasing the survival rate of siniperca chuatsi, simultaneously maintaining the water quality and improving the body immunity and disease resistance of siniperca chuatsi.