When exciting SH-type guided ultrasonic waves in plate-like structures, traditionally utilized piezoelectric transducers often exhibit relatively poor ultrasonic beam directivity, thereby affecting the efficiency and accuracy of defect detection and localization. To address this limitation, the present study proposes an excitation approach based on Lorentz force electromagnetic acoustic transducers (EMAT) for generating highly directive feature guided waves (FGW), which are firmly confined to the welded joints of the plate. The configuration of periodic permanent magnets and a repulsion coil is used for fabrication of the EMAT. The propagation and directivity characteristics of far-field ultrasonic beam of SH-type guided waves in flat aluminum plate are analyzed using multiphysics finite element (FE) simulations in both the frequency and time domains, and are validated experimentally. The results have manifested that the proposed excitation method effectively generates SH-type FGW centered at 440 kHz in 4-mm-thick aluminum friction stir welded joints, demonstrating high mode purity and the presence of energy trapping effect localized to the weld seam. Compared to piezoelectric excitation of SH-type weld guided waves, the proposed method effectively suppresses the generation of lateral Lamb waves, providing solid support for the EMAT aided capabilities of long-distance propagation and defect detection.