The invention discloses a bearing-less rotor ground resonance test method, and belongs to the technical field of bearing-less rotor test. The method comprises the following steps: 1, firstly constructing a bearing-less rotor simulation model and a testbed simulation model, and assembling the two models to carry out ground resonance calculation analysis; 2, verifying equipment in a test system, checking test pieces, debugging each system of the testbed, arranging test points, mounting a sensor, mounting an acceleration sensor at a propeller hub center to measure acceleration speeds in a rotation surface in two directions, mounting an acceleration sensor on a rotor shaft to measure an acceleration speed of the rotor shaft, and providing an overload monitor; 3, releasing an excitation signalby a signal source, transferring the excitation signal to an auto-bank unit via an excitation system, and driving paddles to carry out periodic variable-distance movement by the auto-bank unit; and 4,responding a time history by test points, acquired in the excitation process, on a rotor hub, a flexible beam and the testbed, and processing and analyzing a coupling modal frequency and modal damping of the bearing-less rotor and the testbed, so as to judge whether a ground resonance stability margin exists or not.