In order to study the wavelength-fixed condition of rail corrugation stick-slip mechanism in the metro line, the relationship between the system vibration characteristics and rail corrugation was investigated in terms of frequency domain. Taking the outer rail corrugation on the curved track with steel spring floating slabs as the research object, the finite element method was utilized to construct a three-dimensional solid numerical model of the vehicle-track coupling and the effect of the stick-slip vibration of wheel-rail system on the rail corrugation was explored. In the meantime, combined with the parameter sensitivity analysis, relevant recommendations for the corrugation control were given. The field research shows that significant short-pitch corrugation exists on the outer rail of the curved track, with wavelengths in the range of 42.25~50.91 mm and passing frequencies in the range of 437~526 Hz. The numerical results indicate that the dominant eigenfrequency of 478 Hz of the displacement frequency response curve of the rail contact node is within the range of 437~526 Hz of the passing frequency of rail corrugation in the measured section, and it corresponds to a large displacement amplitude. The formation mechanism of the outer rail corrugation is that the lateral bending vibration of the outer wheel of the guiding wheelset corresponding to the system eigenfrequency of 478 Hz induces the generation of the outer rail corrugation. Appropriate adjustment of fastener vertical stiffness and steel spring vibration isolator vertical stiffness can promote the eigenfrequency of rail corrugation tends to disappear, while changing the rest of the parameters have no effect on the eigenfrequency of rail corrugation, indicating that moderate variation of fastener vertical stiffness and steel spring vibration isolator vertical stiffness is effective in inhibiting the development of rail corrugation.