The invention provides an omni-directional A0 mode lamb wave electromagnetic ultrasonic transducer, and solves the issues of poor unicity method, low energy efficiency and low strength lamb wave excitation in current A0 mode lamb wave electromagnetic ultrasonic transducer. The transducer is characterized in that a cylindrical magnet and a first to Nth hollow cylindrical magnets are arranged from the interior to the exterior on the internal of a shell by a back board in an upright, coaxial and isomorph mode. Two adjacent magnets are arranged in opposite polarities. Annular sub-ring coils of equal widths are arranged on the open end of the shell, on the outer edge of the cylindrical magnet and on the inner and outer edges of the hollow cylindrical magnet. Two annular sub-ring coils of the inner and outer edges of the same hollow cylindrical magnet are coil-reeled in the same direction, two annular sub-ring coils of the inner edge of two adjacent hollow cylindrical magnets are coil-reeled in the reverse direction, two annular sub-ring coils of the outer edge of the cylindrical magnets and the inner edge of the first hollow cylindrical magnet are coil-reeled in the reverse direction. The inner diameter of the first annular sub-ring coils is Lambada-W, and the minimum spacing of adjacent annular sub-ring coils is 0.5 Lambada-W.