The present invention relates to a passive measurement method of overhead transmission line parameters, belonging to the technical field of passive measurement. The method comprises the following steps of: the step 1, obtaining a relative relation of three-phase induced voltages of a tested line; the step 2, employing an inducted current to complete passive measurement of the line itself, and employing the passive measurement method, measuring the inducted voltages and the inducted currents of the tested line in different conditions to complete the grounding loop resistance, the line resistance, the self-impedance parameter and a mutual-impedance parameter of the line. The passive measurement method of overhead transmission line parameters employs a strong electromagnetic environment around the tested line to completely solve the problem that the inducted current of the tested circuit itself is too large or the inducted voltage of the tested circuit itself is too high so that the measurement work is difficult to normally develop when a traditional pilot frequency power source is employed to develop the measurement work of the parameters of the overhead transmission line.