The invention provides a counting device and a counting system for trapping injurious insects. The counting device comprises a box body, a trapping chamber (1), a high voltage power grid (2), an insect collecting hopper (3), an infrared sensor unit (4), an image acquisition unit (5), an injurious insect object table (6) and a main controller unit (8). In the counting device and the counting system for trapping the injurious insects, the injurious insects are counted with the combination of the infrared counting technology and the image counting technology at the same time, the problem of a low accuracy rate caused by single counting is solved, meanwhile because the image acquisition unit collects the image information under triggering of the infrared sensor unit, mutual verifying based on two counting results of infrared counting and image counting is achieved, and accuracy of counting the injurious insects is further improved. In addition, in the counting device and a counting system for trapping injurious insects, when the counting results of the two counting methods are different, retrace further can be conducted according to output results of the counting device.