According to the operational characteristics and requirements of multi-UAVs cooperative attack, a general guidance scheme for cooperative attack of multi-UAVs is proposed. Based on the theory that proportional navigation law(PN) has trajectory uniqueness under the constraint of specific variables, the guidance phase is divided into coordination phase and terminal phase by selecting coordinated variables. The improved Dubins method is used in the track control of coordination phase to realize the space-time synchronous convergence of coordination variables; the 3D space guidance is decoupled into longitudinal plane and lateral plane guidance in terminal phase, and the impact time of swarm is consistent based on the proportional guidance with the same coefficient. Track segment control realizes the space-time cooperation of the swarm considering the constraint of target defense range. The results of numerical simulation and actual flight test show that the scheme has real-time online planning ability, can realize omni-directional saturation attack under the space-time cooperation of large-scale UAV swarm, and has high impact time and space precision.