The invention provides an electronic gun device for high-voltage gas discharge. The electronic gun device comprises a cathode insulator, a high-voltage insulator, a sealing top cover, a first section of gun shell, an insulating trap, an anode, a second section of gun shell, a first focusing coil, a second focusing coil and a deflection scanning coil, wherein the cathode insulator, the high-voltage insulator, the sealing top cover, the insulating trap and the anode are positioned in the first section of gun shell; the first focusing coil, the second focusing coil and the deflection scanning coil are positioned in the second section of gun shell; the cathode insulator, the high-voltage insulator, the insulating trap, the anode, the first focusing coil, the second focusing coil and the deflection scanning coil are coaxial and are sequentially distributed along the axis from top to bottom. According to the electronic gun device for the high-voltage discharge, the cathode life can be greatly prolonged, which is conductive to expanding the application field of a cold cathode electron beam machining technology.