Abstract: A wireless transmission model of combined multi-user selection and cooperative jamming is investigated. Under the Nakagami-m fading channel model, a general-order selection strategy is proposed to select the destination user upon considering the influence of channel feedback delay on channel state information (CSI), and then a cooperative jamming strategy is incorporated to realize secure information transmission. Under the conditions of known and unknown eavesdropping CSI, two different transmission strategies are proposed, and the corresponding exact expressions for the outage probability and the eavesdropping probability of the system are derived. The results of theoretical analysis and numerical simulations show that increasing the order parameter for user selection can improve effectively the security performance of the system.