In order to deal with non-stationary and nonlinear vibration, this paper proposes a time-domain marginal spectrum based on the S transform, and the marginal spectrum is given by the time domain vibration signal spectrum analysis method. The simulation signal processing show that the method is more sensitive to impact energy of vibration signal; it is able to extract the characteristic frequency; it can inhibit signal high frequency components and highlight the characteristics of the low frequency components. The successful recognition of the rolling bearing fault shows that the method can extract weak impact characteristic frequency, which further embody the value of the vibration signal spectrum analysis.