The invention provides an aero engine medium bearing dual rotor test stand loading device, belongs to the field of machining and tools, and relates to an aero engine medium bearing dual rotor test stand loading method. According to the loading method, a loading control system formed by a pressure sensor, a hydraulic system, and a computer control program is adopted for loading; a data acquisition card is connected with a computer through network cables, wherein the computer 18 is provided with a loading system control module compiled by labview and the module is directly called during data acquisition and analysis. The loading method comprises the following steps: installing the loading system, assembling the loading control system, loading and unloading. According to the method, the loading system control program is compatible with the acquisition and analysis program; experimenters timely adjust load size according to real signals and working condition; loading control is simple, accurate, safe and stable so that aero engine medium bearing step-up and step-down loading is realized.