The invention discloses an insect collecting device for an insect killing lamp, and belongs to the field of insect killing devices. The insect collecting device for the insect killing lamp comprises an insect collecting barrel which is detachably connected with an insect killing lamp base plate; and the insect collecting barrel consists of a barrel neck, a barrel body and a base; the base is detachably connected with the barrel body; an escape prevention unit is arranged at the barrel neck; the base consists of a connecting portion and a bottom plate; the bottom plate comprises a central plateand an edge hollowed-out grid; a plurality of grabbing counter bores sunken towards the inside of the insect collecting barrel are arranged on the central plate; and a layer of insect isolation net is arranged above the bottom plate. According to the insect collecting device for the insect killing lamp, the insect isolation net and the edge hollowed-out net grid are not easy to be blocked by insect bodies, and rainwater can be quickly discharged; the escape prevention unit is arranged at the barrel neck, so that insects which are not killed can be prevented from escaping; and the base is provided with the grabbing counter bores, so that the base is convenient to grab by a user with one hand, and the base can be conveniently and quickly mounted or dismounted by the user with one hand. Meanwhile, the problems of inconvenience in drainage, inconvenience in mounting and dismounting, and escape of insects which are not killed can be solved.