This study is about the design and manufacture of a new belt-clamp freshwater fish slitter which is based on the research of characteristic parameters of hypophthalmichthys molitrix.. The fish slitter consists of machine frame, nip-deliver system, cutting system. The key processing parameters of fish slitter can be adjusted, such as belt spacing of nip-deliver system, belt speed, circular saw height of cutting system. The rated power is 3.7 kW, consist of 1.5 kW cutting system motor and 2.2 kW nip-deliver system motor. The final results of experiments with (1.5±0.25) kg hypophthalmichthys molitrix: The level of belt spacing has significant impact on charging, cutting and discharging; it can be 100% success rate when the level of belt spacing is L=40 mm. The level of circular saw height has significant impact on cutting quality, for the fish fully cut open from the head to the tail requires circular saw height not more than 190 mm, for complete preservation of the swim bladder requires circular saw height not less than 210 mm, for not to destroy the fish bile requires circular saw height not less than 180 mm. The fish slitter running stable and has the best cutting quality when the level of belt spacing of nip-deliver system is L=40 mm, the level range of circular saw height of cutting system are from 180 mm to 190 mm.