Reversely invisible bidirectional marking lamp

The invention discloses a reversely invisible bidirectional marking lamp. The reversely invisible bidirectional marking lamp comprises a lamp shell, a lamp holder and light guide plates, wherein two light guide refraction blocks corresponding to indicating arrows on the lamp shell are respectively fixed to the inner side of the lamp shell; each light guide plate is fixed to the other side of the corresponding light guide refraction block; the side, to which each light guide plate is fixed, of the corresponding light guide refraction block is of a slope structure, so that the light guide plates and the lamp shell form a certain inclination angle; the light guide plates are respectively inclined to the directions of the indicating arrows of the lamp shell. The reversely invisible bidirectional marking lamp is simple in structure, low in cost, and high in reliability. When accidents, such as a fire disaster, happen in a tunnel, the personnel escaping direction can be indicated quickly and reliably; the personnel escaping and rescuing opportunities in an accident state are increased.