In order to study the formation mechanism and development properties of rail corrugation in metro， through the establishment of vehicle-track space coupled model and rail corrugation evaluation model， the formation mechanism of corrugation is analyzed in frequency domain and time domain， and the development properties of corrugation are studied by using the corrugation growth rate. Based on the frequency domain analysis， through modal analysis and frequency response analysis of track structure model， it is found that natural frequencies of track structure are close to the passing frequencies of measured corrugation. It shows that the vibration modes corresponding to these frequencies can be more easily excited， which can cause the resonance phenomenon of track structure and form corrugation of corresponding frequencies. Based on the time domain analysis， the time history curves of rail vertical vibration acceleration and rail vertical displacement are calculated by using a vehicle-track coupled model and the frequency domain transformation is carried out. It is shown that there are characteristic frequencies close to the passing frequencies of measured corrugation， which indicates that the vibration of track structure at corresponding frequencies is an important reason to promote the formation of corrugation. The change of vehicle speed has no effect on characteristic frequencies of the corrugation growth rate， which reflects the fixed frequency characteristic of corrugation. With the increase of train operation times， the wavelengths of corrugation corresponding to characteristic frequencies gradually form and develop； the wavelength range and development speed of corrugation gradually increase with the increase of train speed.