The invention provides a cockroach trapper, which comprises a box body; multiple nozzles are arranged on the box body, and sunken to form a gradually shrunken wedge from the outer surface of the box body to the inner part of the box body; the outlet width of the nozzle is 0.5-1.6 cm, and the wall thickness of the nozzle is not more than 1 cm, and the height thereof is not less than 2 cm. Foods are feed in the cockroach trapper, and cockroaches are flied from the surface of the box body or climbed into the wide opening of the nozzle to enter the trapper; for the outlet of the nozzle is very small, and only cockroaches can access, cockroaches can pass through the nozzle to get out by making the cockroach body in parallel to the nozzle channel; moreover, the nozzle height and the wall thickness design determine that the cockroaches cannot enter the nozzle channel in parallel under the condition of not bending; thus the cockroaches get trapped in the trapper, and cockroaches can be used for feeding ducks after being starved or drowned; for the cockroaches are high protein food, the cockroach trapper overcomes the drug risk of the cockroach drug and the pollution for the cockroach corpse cannot be recycled.