The invention discloses a sewer safety gully lid. The gully lid comprises a flowing water top lid which is provided with grids which are mutually connected, and is characterized by comprising a sewage draining opening enclosed by the mutual connection of lateral walls of the gully lid. The lateral walls of the gully lid are internally provided with multiple square inner grooves, the inner grooves are internally provided with multiple lifting supporting rods corresponding to the inner grooves, the supporting rods are correspondingly connected to the portion, corresponding to the sewage draining opening, at the edges of the flowing water top lid, the inner cavities connected with the square inner grooves are arranged at both sides of each lateral wall of the gully lid, and are internally provided with supporting rod lifting mechanisms for synchronously driving the supporting rods to lift and fall, and the flowing water top lid is provided with an alarming lamp tube controlled by a rainwater sensor. The sewer safety gully lid is simple in structure and convenient to operate, the gully lid can be uplifted under the condition of heavy rain, an alarming lamp arranged on the flowing water top lid can be utilized to alarm passers-by when the rainwater submerses the gully lid, and thus the personal injury to the walking passers-by is avoided.