The invention provides an array electromagnetic ultrasonic resonance probe for rough-surface metal thickness measurement and a method. The probe is composed of a permanent magnet, an excitation coil,a detection coil array group and a flexible material skeleton. The excitation coil is arranged at the center of the bottom of the permanent magnet. The detection coil array group is formed by a plurality of detection coils that are distributed around the excitation coil to form a detection coil array. The permanent magnet generates a strong constant magnetic field; when a pulse excitation currentflows through the excitation coil, an eddy current is generated on the upper surface of a test piece and the generated eddy current generates a Lorentz force under the constant magnetic field effect of the permanent magnet, a mass point vibrates, and thus an ultrasonic wave is generated on the upper surface of the test piece; the ultrasonic wave is propagated in a conductive material and is reflected to form multiple beams of ultrasonic echo waves when meeting a rough metal lower surface; the multiple beams of reflected ultrasonic echo waves are received by the detection coils encircling and being distributed around the excitation coil; and after signal processing, thickness distribution of the conductive material at the rough surface is calculated.