Vibrio freeze-dried powder should not be used in the molting period of Penaeus vannamei. During molting, Penaeus vannamei will consume a lot of energy and minerals in a short time, especially trace elements such as calcium, magnesium and phosphorus. During this period, the demand for calcium is relatively large. Vibrio freeze-dried powder is only antibiotics and chemical fungicides, and cannot supplement trace elements. Therefore, Vibrio freeze-dried powder cannot be used during molting of Penaeus vannamei.