Network Reconnaissance - Multi-UAV cooperative reconnaissance for target search, localization, and tracking has attracted much attention in both civil and military applications, where strategies need to be designed for UAVs to finish the reconnaissance task cooperatively and in the time optimal manner. Different from the state-of-theart of recent research where all the UAVs involved are equipped with homogeneous payloads, this work exploits payload diversity to enhance the time efficiency of the cooperation and proposes a fast multi-UAV cooperative reconnaissance (FMUCR) method. FMUCR groups UAVs in pairs. In each pair, one UAV is equipped with a passive positioning radar, referred to as p-UAV, while another is equipped with an active positioning radar, referred to as a-UAV. FMUCR exploits the large detection range and rough target location detection of passive radar to enable fast search and directional tracking of a target, while the precise target position calculation of active radar to enable accurate tracking of a target. Specifically, the task area is partitioned into subareas according to the number of UAV pairs. Each UAV pair conducts target search, localization, and tracking in one subarea, where the p-UAV leads searching and preliminary tracking of targets, while accurate tracking of targets are taken over by the a-UAV. Algorithms for off-line path planning and on-line path planning are designed, respectively, for target search and target tracking. The comparative simulation demonstrates that, FMUCR can greatly shorten the target discovery time with little loss in target tracking accuracy.