Abstract: Although Transient Electromagnetic Method (TEM) has been widely used in resource exploration and engineering exploration, it still has some problems to be solved. In order to improve the interpretation precision, some new techniques and methods must be introduced. Because TEM data can be converted into a virtual wave-field by a mathematical formula; the achievement of multi-aperture electromagnetic model simulation shows that the correlation of multi-aperture TEM does exist; echo waves of the same geological body from adjacent positions have a good correlation. Therefore, it is feasible for TEM data to realize multi-aperture synthesis imaging. With the basic idea of synthetic aperture radar, a new set of data processing methods have been proposed which use related superposition techniques to fulfill multi-aperture data synthesis. After the extraction of transient electromagnetic pseudo-wavelet, the traditional profile-based approach has been developed into the multi-aperture synthesis relative to measuring points, and the traditional single-point approach has been developed into the point-by-point survey multiple coverage technique. The technology of synthetic aperture thereby greatly improves the resolution of transient electromagnetic method and enriches the connotation of it from the perspective of wave-field. Thereby, more information can be extracted from the transient electromagnetic method which can not be got by conventional methods and it's more beneficial to imaging. It has been shown that synthetic aperture imaging is feasible from the processing results of designed models and measured data. The research achievement opens a new approach to develop transient electromagnetic imaging technique and improve the resolution.