Abstract: High-energy electron beam power density distribution and its spatial pattern are important factors for the quality of electron beam. On the basis of analyzing the characteristics of high-energy electron beam,a novel electron beam testing method and testing device were proposed. Based on characteristics and the relationship between electron beam deflection signal and scanning signal,a signal acquisition structure was developed. High-frequency,high-speed dada transfer,sharing of external clock source and acquisition trigger mode were dealt with a PCI-1714 card. Serial communication,data collection process and segmentation preprocess method were described in detail. The results show that the developed system could effectively capture the original high-energy transient signal of electron beam, which provided a method for analysis and processing of electron beam spatial data.