Abstract: The present invention belongs to the technical field of flutter tests for rotorcrafts, and discloses a ground whirl flutter test system and test method for a rotorcraft. The ground whirl flutter test system for the rotorcraft comprises a hardware part and a software part. The hardware part comprises a rotor test article, a support system, force loading devices, vibration signal sensors, load cells, vibration signal acquisition cards, an industrial control computer, force signal output cards, a power amplifier and load cell signal acquisition cards. The software part of the ground whirl flutter test system for the rotorcraft comprises a rotor force and moment calculation program and a multi-input multi-output force control program running on the industrial control computer. The method can reserve all dynamic characteristics of the aircraft structure, is not restricted by the size of a wind tunnel test chamber section, does not require dynamic scaling of aircraft structures.