The invention relates to preparation of hollow capsules, specifically to marine animal fish skin gelatin hollow capsules and a preparation method thereof. The fish skin gelatin hollow capsules comprise the following four components by weight, 15-50% of fish skin gelatin, 0.1-30% of a plasticizer, 0.001-10% of a surfactant and 40-80% of water. According to the present invention, the adopted fish skin gelatin has characteristics of good film formation, good safety, good biocompatibility and good biodegradability, is a high quality protein resource, and has effects of human immunity increase and memory enhancement; the preparation method has characteristics of simple operation, easily available raw materials and significantly reduced hollow capsule production cost; and the obtained hollow capsules do not have the excessive heavy metal problem, do not contain hydroxybenzoate esters and other harmful preservatives, and do not adopt ethylene oxide and other sterilization processes.