Automatic device for killing fly

An automatic device for killing flies belongs to a device for trapping flies, which is composed of a transparent upper cover, a transparent box body, bait, water for drowning flies and a small plug. The utility model is characterized in that the upper cover is an inverted cone, and the top end of the inverted cone is provided with a through opening; the upper cover and the box body are made of transparent materials. The bait is used for luring the flies into a space which is formed from the upper cover, the box body and the water for drowning flies, so that the flies are easy to go into the space but difficult to go out and the flies can be drowned in the end. The utility model has the characteristics of simple structure, high fly killing efficiency and no need of any energy resource.