The setting principle of the power frequency distance protection is usually used for the setting of the time domain distance protection. However, it may result in operation failure or maloperation. So the setting method of the time domain distance protection based on the R-L model is proposed in this paper. The influencing factors of the measurement impedance calculation results of the time domain distance protection are analyzed. Then the protection action boundary is confirmed according to the directional impedance characteristic circle after considering various influencing factors and the margin. Finally, the setting method of the time domain distance protection is presented. The correctness of the proposed setting method is verified by ATP-EMTP simulation results. With this setting method, the sensitivity and reliability of time domain distance protection can be improved.