The invention relates to a freshwater fish pretreatment processing production line. The freshwater fish pretreatment processing production line comprises a fish inlet hopper device, a fish head, tail,belly and back orienting device, a fish scale removing device, a fish body conveyor belt device, a head and tail slitting device, a fish body sectioning device, a fish body internal organ sucking andcleaning device and a fish body internal black membrane removing device, wherein the fish inlet hopper device, the fish head, tail, belly and back orienting device, the fish scale removing device andthe fish body conveyor belt device are connected in sequence, and the head and tail slitting device, the fish body sectioning device, the fish body internal organ sucking and cleaning device and thefish body internal black membrane removing device are arranged on the fish body conveyor belt device in sequence. The freshwater fish pretreatment processing production line is high in automation degree, can synchronously complete a series of fish pretreatment processes such as fish body head, tail, belly and back orienting, fish scale removing, head and tail slitting, fish back sectioning, internal organ removing and black membrane cleaning, is high in production efficiency and automation degree, and can create obvious economic benefits for enterprises.