The invention discloses an anti-big bird hazard device for a jet engine, which relates to power plant arrangement on an airplane, and provides a device capable of preventing a jet engine from being damaged by big birds. Grates are arranged, the cross points of the grids of the grates are provided with tapers, the cross section of each grid adopts a streamline structure, and the device is additionally arranged at the inlet of the jet engine when in use. Since the cross points of the grids of the grates are provided with the tapers, the cross section of each grid adopts the streamline structure, and the device is additionally arranged at the inlet of the jet engine when in use, the device is in symmetrical streamline on the direction of incoming flow, not only is the air resistance reduced, but also no lift force generates on the direction vertical to the incoming flow, thus being capable of tearing a big bird flying into to ensure that the big bird passes from different grids; and the torn big bird has segregation function on the blades of an engine to prevent the occurrence of big bird hazards, thus preventing the jet engine from being damaged by the big bird.