The invention discloses a preparation method of a cow-dung fish feed. The preparation method of the cow-dung fish feed comprises the following steps of pouring 1 
kilogram of the Baiyibao feed 
fermentation agent into 50 kilograms of water so as to carry out 
dilution by performing uniform stirring; putting 
cow dung and a feed together into a blender, and mixing the 
cow dung and the feed by carryingout stirring-mixing for 2 minutes; and then, adding a strain 
dilution, and carrying out stirring for 6 minutes. When no blender is available, the preparation of the cow-dung fish feed is carried by performing stirring by using a 
shovel according to a less-to-more principal, namely pouring the strain 
dilution into a small amount of the feed and the 
cow dung, and carrying out uniform stirring untilno 
mass exists; pouring the small amount of 
raw material to be fermented into the remaining feed and cow dung, and carrying out uniform stirring until no 
mass exists; putting the mixed 
raw material tobe fermented into a plastic container or a 
cement pond or a pit lined with a plastic sheeting until the plastic container or the 
cement pond or the pit lined with the plastic sheeting is fully filledwith the mixed 
raw material to be fermented after bing tightly pressed; and then, exhausting air, carrying out sealing by using a plastic sheeting until the plastic container or the 
cement pond or the pit lined with the plastic sheeting is completely sealed, carrying out 
fermentation at an appropriate temperature of 25-35 DEG C for 5-10 days until no 
odor is produced and a smell of 
alcohol emerges so that the 
fermentation is successfully done. By fermenting the prepared cow dung and feed, the cow-dung fish feed is capable of improving 
water quality, as well reducing mortality of fry.