The invention discloses a rotating speed collection device and method for preventing a nuclear electro-magnetic pulse. Two electromagnetic induction probes form a differential electromagnetic induction sensor, and the rotation of a fluted disc enables the differential electromagnetic induction sensor to generate a balance signal, wherein the balance signal is transmitted through a wire harness. Acommon mode choke and an isolation transformer can eliminate the common mode interference in the balance signal, and the common mode signal is converted into an unbalance signal required by a controlsystem. The differential electromagnetic induction sensor can enable the unbalance signal to be converted into a balance signal which can be conveniently transmitted on the wire harness, and achievesthe mutual cancellation of the magnetic field coupling of strong electromagnetic pulses and does not affect the generation and transmission of a rotating speed signal. The transmission of the balancesignal on the wire harness can eliminate the external radiation interference and the transmission interference with the outside. The device and method can eliminate the sensor coupling generated underthe strong electromagnetic pulse coupling and the common mode coupling on a cable, guarantee the normal operation of a system, and is lower in manufacturing cost.