To avoid the mechanical wear, machine noise and improve the service life of the conventional permanent magnet synchronous generator (PMSG), a bearingless PMSG (BPMSG) is proposed in this paper. The novel BPMSG which integrated the advantages of the conventional PMSG and magnetic bearings has a wider range of application in aeronautics and astronautics, national defense, new energy, and etc.. To begin with, the principles of suspension and the electric power generation are described in detail. Then, the flux linkage and induced voltage equations are derived. Based on the Maxwell tensor method, the mathematical models of the suspension force and electromagnetic torque are established and verified by the finite element analysis (FEA). Parameter analysis is utilized to acquire higher performance, however, the suspension and power generation performance is obviously affected under variable load and speed conditions which shown in the dynamic analysis results. Thus, a forecast direct control strategy based on flux-linkage observation is proposed to remedy the defects of the unstable suspension force and generating voltage caused by the operation changing suddenly. The simulation results show that that the suspension force quickly return to stability within 0.02 second, the overshoot of voltage is reduced to 8.18% and the steady adjustment rate of voltage is 0.45%. Finally, a prototype of a 2.2kW BPMSG is manufactured and tested. The experiment results show that the proposed BPMSG can not only operate steadily under variable load and speed condition, but also have good suspension performance and power generation quality.