The utility model relates to a falling-rock preventing reinforced concrete open cut tunnel structure. Most mountainous areas are sharp in slopes and narrow in fields, and are short of the conditions to extend the tunnel portal and arrange the falling-rock preventing structure, under the limit of the engineering condition of the tunnel portal, the phenomena of bridge abutment in tunnel or adjacent bridge and tunnel are common, and the normal tunnel portal is unsuitable. According to the utility model, an arc-shaped reinforced concrete lining structure is covered above a bridge main body structure; the bottom end of the reinforced concrete lining structure is arranged on a pile foundation by a pile block longitudinal beam; a plurality of ventilating and lighting holes are arranged on side walls and the arc-shaped parts of the two sides of the reinforced concrete lining structure, and a rubber protective layer is arranged out of the reinforced concrete lining structure. An exterior environment is relatively isolated from a driving environment according to the utility model, so that the environment in the tunnel and the outside cannot influence each other; the structure is excellent in endurance performance, the later operation and maintaining work load is low, and the cost is low.