The invention provides a preparation method and application of a sea 
bdellovibrio bacteriovorus ecological preparation, and relates to a sea microbial ecological preparation and a preparation method of a 
bdellovibrio bacteriovorus preparation for 
mariculture. The preparation method comprises the following steps of: preparing a host 
bacteria suspension; separating and purifying 
bdellovibrio bacteriovorus; and propagating and culturing 
bdellovibrio bacteriovorus. The preparation method is characterized in that after 
pseudomonas stutzeri is connected with an incline and is activated, adding 
physiological saline in a 
test tube to prepare the bacterial suspension; then propagating and culturing with 
nutrient bouillon; adding a flocculating agent in the obtained bacterial suspension; standing and precipitating after uniformly shaking; adding the 
physiological saline to obtain 1012 cfu / mL of host 
bacteria suspension; separating and purifying the 
bdellovibrio bacteriovorus of collected sea and bottom 
sediment samples with a double 
agar plate method; pouring culture media containing the host 
bacteria suspension and the collected samples into sea 
agar in the lower layer for culture after uniformly mixing; and adding the host bacteria and the 
bdellovibrio bacteriovorus obtained by separation into sterilized natural sea, and culturing until the concentration of the bdellovibrio bacteriovorus is 108 to 109 pfu / mL for future use.