The invention discloses a construction method of an energy-dissipation and seismic-mitigation combined shed tunnel structure capable of resisting the landslide collapse body impact. The energy-dissipation and seismic-mitigation combined shed tunnel structure comprises top beams, shed tunnel plates, a composite buffer cushion layer and energy dissipation and seismic mitigation devices. The top beams are arranged on the two sides of the ground of a to-be-protected area. The shed tunnel plates are supported at the tops of the top beam through the energy dissipation and seismic mitigation devices.A waterproof layer is constructed on the top surface of one shed tunnel plate; then a foam cushion layer, a steel plate layer and a geocell reinforced soil layer are constructed sequentially, geocells on the steel plate layer are stretched, paved, and unfolded fully in the construction process, each geocell at the end part is fixed by using a pin, the space of each geocell is filled with a soilbody fully, and then the geocell is filled with soil gradually to a corresponding designed elevation to form a composite buffer cushion layer. The construction is simple and convenient; the service life is long; the the self-weight of the shed tunnel structure is reduced, the landslide collapse body impact resistance and the energy absorption and shock absorption performance of the shed tunnel structure are improved, and the safety and stability of the shed tunnel structure are improved. The method is especially suitable for shed tunnel structure construction of landslide disaster frequent road sections.