The invention discloses a field multi-conductor transmission line coupling radiation sensitivity test method, which belongs to the technical field of electromagnetic interference test. The method comprises steps: an interference line weakly coupled with a transmission line is erected at a position parallel to a to-be-tested transmission line, two ends of the interference line are respectively connected with signal sources and impedance is matched, a field multi-conductor transmission line coupling mode and a multi-conductor transmission line model equivalent to the field multi-conductor transmission line coupling mode under two-port excitation are built, the signal source connected at two ends of the interference line are initialized, and the port voltage of the to-be-tested transmission line is detected. A transmission line radiation sensitivity prediction experiment is converted to a multi-conductor transmission line experiment under the two-port excitation, and the cost is reduced while the high test precision is kept.