The invention discloses a limited space fire blast simulation and explosion pressure relief and explosion suppression experiment platform and a method. The platform comprises an experiment cabin, an ignition system, a suppressing system, a gas distribution system, a data acquisition system, a control system, and a computer, the experiment cabin, which is a three-dimensional cabin, is provided with inhibitor nozzles reserved on the top surface and window type explosion vents, a plurality of pressure relief membrane frames with different sizes which are of square boss structures are nested through high-strength bolts to form the window type explosion vent, and in a fire blast experiment, the window type explosion vents are arranged on the sidewalls of the experiment cabin; in a flashover and backdraft experiment, the sidewalls of the experiment cabin are arranged as door type explosion venting panels, and the door width can be adjusted by a high-strength bolt nesting method. The platform and the method can be adopted to carry out fire blast and explosion suppression experiments in the limited space of a building with real dimensions under different concentration distributions, different explosion venting conditions, different ignition positions and different explosion suppression conditions, providing related experimental parameters for the creation of explosion venting parameter prediction model in limited spaces of buildings and the proposal of a highly effectively explosion suppression technique.