Abstract: A₀ mode of Lamb waves is widely used in defect detection and monitoring with large scale and high efficiency in plate-like structures due to its shorter wave length compared with other mode in the specified frequency range, which leads to high sensitivity to small damages. A unidirectional A₀ mode electromagnetic acoustic transducer (EMAT) is developed and it consists of a meander coil on flexible printed coil (FPC), and a horseshoe magnet. The experimental results verify that the developed transducer can effectively produce the pure A₀ mode in an aluminum plate. In order to realize flaw detection and reconstruction for the aluminum plate, a new electromagnetic ultrasonic scan imaging technology was developed. The damage index was defined by using virtual time reversal method. The combination of probabilistic damage algorithm and data fusion algorithm was used to deal with multiple sets of data. The location and imaging of simulated defects on the aluminum plate were well achieved accurately.