The invention discloses an experimental system used for simulating severe accident conditions of the containment of a nuclear power plant and an implementation method thereof to overcome the problem that comprehensive simulation of severe accident conditions of the containment of a nuclear power plant cannot be realized in the prior art. The experimental system comprises an experimental container, a first pressure sensor arranged in the experimental container, a data acquisition system, an exhaust pipeline, an air supply system, a hydrogen supply system, a spray system, an aerosol supply system, a cable combustion product supply system, a water vapor on-line supply system and at least four sampling pipelines, wherein the data acquisition system is connected with the experimental container through multipoint thermocouples; the exhaust pipeline, the air supply system, the hydrogen supply system, the spray system, the aerosol supply system, the cable combustion product supply system, the water vapor on-line supply system and the at least four sampling pipelines are connected with the experimental container; and the aerosol supply system is connected with the spray system. The experimental system provided by the invention has a reasonable structure, can authentically and comprehensively simulate severe accident conditions in the nuclear power plant and carries out hydrogen elimination performance testing on a passive hydrogen recombiner on the basis of simulation results; moreover, testing results approximately represent actual working conditions, so good reference standards are provided for researching and designing of the recombiner.