An experimental system a method for studying jet impact characteristics at a core outlet of a fast reactor are provided. The system includes a jet impact main loop including a water storage tank, plunger pumps, a filter, preheaters, a jet impact chamber, a heat regenerator, a condenser, valves, flow meters and pipelines connecting these facilities; a cooling loop including cooling tower, a cooling pump, a regulating valve and a flow meter; and a makeup water loop including a deionized water machine, a makeup water tank and a plunger pump. Water in the water storage tank flows to the heat regenerator via the plunger pump, is preliminarily heated by the heat regenerator and then is divided into three branches to flow to the jet impact container.