To satisfy the demand for batch cutting and processing of bowl shaped jellyfish, a slender jellyfish cutting automatic cutting blade was designed for bowl shaped jellyfish. The curvature and deflection of the blade were numerically simulated using the Frenet-serret frame formula combined with the shape of the jellyfish skin, and the blade trajectory was obtained as a spatially non-isometric spiral. Two special cutting blades for bowl shaped jellyfish were designed by using heat-treated 440C stainless steel as the material for the blades, taking into account the actual working environment. The mechanical properties of the two blades were analyzed and the stress value of the convex blade was only 53.4% of that of the concave blade; the wear analysis of both concave and convex cutting blades was carried out under the same conditions and it was concluded that the wear of the concave blade was twice as large as that of the convex blade; experiments have proven the reliability, stability and better cutting results of convex blade. Through comprehensive analysis, the convex blade is used as an automatic cutting blade for slender jellyfish filaments and is able to satisfy the needs of batch cutting and processing of bowl shaped jellyfish.