Abstract: In order to provide a load environment for the wear life test of half-size water-lubricated bearing in the nuclear primary pump with canned motor, an axial load magnetic simulation device was developed, and its single properties, interface properties or service performance under the magnetic-liquid composite were researched. Taking wear mass as the key parameter of life assessment, a prediction-correction test scheme of water-lubricated bearing wear life for primary pump was purposed and its load requirements was analyzed. A structure scheme of electromagnetic loading system whose static loading and dynamic excitation were independent was obtained by the independent axiomatic design ideas. Simulation and experimental verification of its magnetic characteristics were conducted, and the magnetic-liquid composite properties were analyzed based on the rotor-bearing-loading system dynamics model. The results show that the device can realize static loading 10t, impulse and harmonic exciting. When the current is the same, the magnetic force under the magnetic-liquid composite is less than the single magnetic force without composite. Therefore, the magnetic-fluid coupling effect should be considered as a key factor for the design of electromagnetic loading device.