A low-speed wind tunnel study of active flow control for improving aerodynamic performance of delta wings at high angles of attack is presented. A dielectric barrier discharge actuator driven by pulsed nanosecond voltage is used to create periodic perturbations along the leading edge of delta wing. Four wings with sweep back angles of Λ = 30°, 47°, and 60° are tested. Data obtained by means of force measurements show that the effectiveness of the actuation strongly depends on the wing’s sweep angles and the actuation frequency. For Λ = 30°, 47° delta wings, the pulsed actuation could increase the lift at post stall regions. For Λ = 60° delta wing, the pulsed actuation at the leading edge almost has no effect on its aerodynamic performance. At last, the control mechanism is discussed.