Abstract: In order to optimize the preparation process of the fish oil micropowder and analysis its stability, the preparation technology of micropowder of fish oil from fish meal processing by-product was investigated by spray drying, composite wall materials were selected. The effects of core wall ratio, solid concentration, emulsifying temperature, inlet air temperature, spray pressure and feed flow rate on the microcapsulation efficiency were investigated. The results showed that the Arabia gum/β-cyclodextrin/corn syrup (2:1:6, weight ratio) was a suitable wall material, the optimum conditions for the preparation of micropowder were as follows: Core wall ratio 32%, solid concentration 25%, emulsifying temperature 52 ℃, air inlet temperature 206 ℃, spray pressure 35 MPa, feed flow 300 mL/h. Under thses condition, the embedding rate of fish oil was 92.66%. The surface of micropowder particles was smooth, without cracks or holes, and had good water solubility. The storage stability of fish oil micropowder was significantly higher than that of non microencapsulated fish oil (P<0.05), and the microencapsulated fish oil with antioxidant had better antioxidant capacity.