Central-through-sunken-part-reinforced front longitudinal beam

The invention provides a central-through-sunken-part-reinforced front longitudinal beam. The central-through-sunken-part-reinforced front longitudinal beam comprises a main side plate and a sunken side plate. A closed cavity is defined by the main side plate and the sunken side plate, a central sunken groove is formed in the sunken side plate, and the sinking direction of the central sunken groove faces the main side plate. The central-through-sunken-part-reinforced front longitudinal beam has the advantages that as the central-sunken-groove cross section design is adopted, the problem that a deformation form of a front longitudinal beam with a traditional cross section is instable is effectively solved; as the cross section form of the front longitudinal beam is changed, under the conditions of the same material and the same mass, the safe collision energy-absorption requirement of the front longitudinal beam is effectively met, the crushing force and the energy absorption index are effectively increased, and the light-weight requirement of a car body is met.