Active electromagnetic (EM) armor is a new kind of active defense system, which consists of advanced detector, control system, high pulsed-power supply, and an EM launcher (EML). The EML is a key component of the active EM armor, which includes drive coil, interception projectile, insulator, and pedestal. With the EML, electric energy provided by the high pulsed-power supply can be transformed into kinetic energy of the interception projectile. Hit by interception projectiles, the invading object can be destroyed totally or deviate from its trajectory. In this paper, the make up and working principle of the active EM armor are introduced. The field-circuit coupled model during the working process is established. With finite-element-analysis codes, the field-circuit coupled analysis of the EML is accomplished during launching process of the interception projectile. The laws of current wave, EM force acting on the interception projectile, and its velocity and displacement versus time, are achieved. The effects of the changes of the interception projectile's initial position and the capacitor's charging voltage on the launch velocity of the interception projectile are also analyzed. In order to verify the simulation results, experimental installation is fabricated, and experimental data match well with simulation results.