The invention relates to the technical field of health food, and in particular to an algae oil soft capsule and a preparation method thereof. The algae oil soft capsule is prepared from a content and a capsule wall material, and the content is prepared from the following raw materials in parts by weight: 30 to 50 parts of algae oil, 6 to 20 parts of linolenic acid, 10 to 20 parts of amino acid, 2 to 10 parts of lecithin, 2 to 10 parts of cephalin and 2 to 8 parts of vitamin E, wherein the amino acid is at least one of phosphatidylserine, asparaginic acid, lysine, tyrosine and glutamic acid; main additives of the capsule wall material are prepared from gelatin, glycerinum and water. The algae oil soft capsule provided by the invention is rich in various beneficial ingredients for the growth and development of the brain, capable of remarkably enhancing the memory ability and improving intelligence, simple in preparation technology, convenient to carry, accurate in dosage, and safe and reliable.