The invention discloses a full-automatic fish skin stripping method based on a fish skin stripping device. The fish skin stripping device comprises a clamping mechanism, an annular cutting knife (1), a separating knife (2) and a skin stripping mechanism (3); the clamping mechanism comprises a gill hook (4) and a tail clamping mechanism (5), the annular cutting knife is located at the eccentric position of a central axis between the gill hook and the tail clamping mechanism, and the separating knife and the skin stripping mechanism are located at the gill hook side; a fish body to be skinned is horizontally clamped front and back through the clamping mechanism, the annular cutting knife performs annular cutting around the fish body, the separating knife stretches into the fish body from the annular cutting position to separate fish skin from the fish body, then the annular cutting knife performs longitudinal cutting on the fish skin in the length direction of the fish body, and in the skin stripping process of the skin stripping mechanism, the tail clamping mechanism is loosened. According to the full-automatic fish skin stripping method, automatic separating of the fish skin is achieved, the fish skin stripping efficiency is improved, and the fish skin is prevented from being destroyed.