Motion stability of the high-speed maglev vehicle under steady aerodynamic load was studied. The dynamic model of the high -speed maglev vehicle on the curved guideway considering influence of aerodynamic loads was established. The critical speed concept of the maglev vehicle considering aerodynamic loads′ effect based on eigenvalues was presented. Vehicle speed, control parameters, and aerodynamic coefficients to make the critical speed of the high-speed maglev vehicle change in the critical state were also analyzed. The results show that when the system reaches the critical state, it has two critical speeds. Under the conditions in the critical state, the position control parameters vary from 20 000 kN/m to 2 000 kN/m, and aerodynamic coefficients vary from 0.05 to 0.01, the critical speed gets larger. When the real part of the eigenvalue is zero, but the imaginary part is not zero, the first kind of critical velocity occurs. When both the real part and the imaginary part of the eigenvalue is zero, the second kind of critical velocity appears. Instability is caused by the change from the equilibrium position for the curved guideway and wind loads. Aerodynamic downward force and centrifugal wind loads are not good for stability, but aerodynamic upward force and centripetal wind loads improve stability. The horizontal angle can be matched with the centripetal force, but the vertical angle is allowed to be set in a small range.