A capacitor discharge unit (CDU), consisting of domestic Metal-Oxide-Semiconductor（MOS） controlled thyristor (MCT) and high-voltage ceramic capacitor, was designed and prepared in order to study the discharge characteristics of CDU. The volume of the CDU is 40 mm(L)×25 mm (W)×8 mm(H). The CDU circuit inductance is about 10 nH, and the resistance is about 100 mΩ. The R-L-C zero input response equation of CDU circuit was analyzed, and was verified by the experiment of short-circuit discharge of CDU load. It is found that the key parameters of CDU, such as the peak current, rise time of peak current and discharge time of high-voltage capacitor all increase with the increase in capacitance value; the peak current increases with the increase of discharge voltage, and the peak current rise time remains constant. The function efficiency of CDU was verified by micro-chip exploding foil initiator(Cu bridge foil 35 mΩ) and boron-potassium nitrate pellet(B/1.50 μm, pressing density/1.57 g·cm^-3), under the condition of 0.36 μF/1.20 kV, the measured peak current of circuit is 2.032 kA, the voltage at both ends of the bridge foil is 0.9273 kV, the delay time between peak current and voltage is 32.4 ns, the burst time is 168.2 ns, and the burst point power is 1.490 MW, and the CDU can reliably ignite BPN pellet by flyer impact. Results show that the CDU based on the domestic MCT and high voltage ceramic capacitors is basically suitable for high-current pulsed initiating devices such as exploding foil initiator, but its comprehensive performance still needs to be improved.