The invention discloses a preparation process of scale jelly, relating to the technical field of processing of fish products. The preparation process comprises the following steps: (1), unfreezing and rehydrating scales; (2), cleaning; (3), pretreating, namely, respectively performing acid treatment, alkali treatment and enzyme treatment on the scales, cleaning the scales with flowing tap water until the pH is 7.0, washing twice with distilled water, draining the wet scales until no water drops, placing the scales in a beaker, adding distilled water in a certain ratio, and sealing with aluminum foil paper to prevent water from evaporating; (4), extracting gelatin, namely, extracting gelatin under the conditions that the temperature is 70-100 DEG C, the time is 0.5-4 hours, the ratio of the wet scales to the distilled water is 1 to (3-8) and the pH of water for extracting the gelatin is 7.0; (5), suction-filtering, namely, performing vacuum suction filtration by a Buchner funnel, and filtering scale residues with nylon filter cloth; and (6), gelling, namely, gelling the scale gelatin in a container at a temperature of -10 to 10 DEG C. The scale jelly is high in yield, and high in calcium content; nutritional ingredients are not damaged; the preparation process is simple, gelatin is convenient to extract, and the cost is low.