The invention relates to a slowly-sinking puffed compound feed for channel catfish and a preparation method thereof and belongs to the technical field of production of puffed feeds for aquatic products. The feed contains fish meal, pork powder, rice protein powder, fermented soybean meal, rapeseed meal, soybean meal, rapeseed dregs, cottonseed meal, rice bran, flour, wheat, soybean oil, monocalcium phosphate, bentonite, 98.5% lysine hydrochloride, 99% DL-methionine, choline chloride, a compound vitamin premix, 35% vitamin C phosphate, vitamin A acetate, vitamin E, a composite mineral substance premix, a micro-ecological preparation, an antioxidant and a mildew preventive. The feed is conveniently eaten by the channel catfish, improves the feeding rate, has good water resistance and has not higher the technical requirement for feeding. In addition, intestinal health of the channel catfish can be improved, then the feed utilization efficiency of the channel catfish can be improved, eventually the growth speed and yield per unit volume of the channel catfish can be improved, and the breeding benefits of farmers can be improved.