Focusing the influence of high-lift configuration of an airplane on wing aerodynamic characteristics， an experiment is conducted in NH-2 low-speed wind tunnel over a swept constant chord half-model (SCCH) high-lift configuration of a civil aircraft. In this experiment， the Mach number is 0.2 and the Reynolds number is 1.85×106. The effect of salt deployment angle， gap and over-lap on efficiency of high-lift configuration is investigated. Based on the test results， best slat parameters of this model are obtained for both take-off and landing configurations. The results show that both the stall angle of attack and the maximum lift coefficient increase with the slat deployment angle increasing from 18° to 24°， and only the stall angle of attack increases while the maximum lift coefficient does not change obviously when the angle increasing from 25° to 31°. The best slat gap width is from 1.5% to 2.0% for take-off configuration， while 2.0% to 2.5% for landing configuration. The best over-lap is around 1.0% for take-off configuration， while －1.0% to 0% for landing configuration. The best slat gap width presents increasing trend with the increase of the slat deployment angle.