In this paper, a new cooperative guidance law is designed for enabling multiple vehicles to simultaneously intercept a maneuvering target. The guidance system is naturally decoupled into normal and tangential direction to achieve perfect interception and terminal impact time constraint, respectively. Based on augmented ideal proportional navigation guidance, the normal acceleration command is derived to intercept maneuvering target. Then, taking advantage of the speed controllability of UAVs, we design an implicit salvo cooperative guidance law along the direction of relative velocity by leveraging sliding mode control theory. The feasibility and performance of the proposed cooperative guidance law are demonstrated through numerical simulations.