To improve the existing fault location methods in multi-terminal transmission network, a novel method based on transient traveling wave is presented. S-transform is applied to the aerial modal components of synchronized measured voltages at all the terminals to extract the Nyquist frequency components of transient traveling waves. The moment corresponding to the maximum component in the Nyquist frequency component is exactly the initial traveling wave arrival time. Using the wave velocity corresponding to the Nyquist frequency component as the calculation wave velocity, the problem of the wave speed uncertainty is solved. According to the number of T nodes passed through by each line, all the lines can be classified into branch section and artery section. Based on double-terminal traveling wave theory and the result of the indentification theory for fault section, the final fault distance can be achieved. The simulation results prove good performance of the proposed method.