Abstract: In view of problems that traditional detection device of identification card cannot detect card effectively at assigned area and has error identification area, a directional antenna with narrow band and high gain was designed. Through changing gain and direction angle of omnidirectional antenna of the traditional detection device of identification card, width of horizontal lobe is reduced from 180° to less than 90°, parameters of length, width and matrix arrangement mode of the antenna are analyzed and optimized by using Ansoft HFSS electromagnetic simulation software, so as to realize good performances of narrow band, direction and high gain. The actual application shows that the antenna can ensure uniqueness detection device of identification card well accord with relative requirements of AQ 6210-2007 and AQ 1048-2007.