The present invention relates to an inertial electrostatic confinement fusion apparatus for electron injection neutralization, which includes a cathode spherical net, an anode, a cathode high-voltage introduction supporting rod, an electron gun for high-energy electron injection, a vacuum system and a high-voltage power supply system. Neutralizing electrons are injected by the electron gun for the high-energy electron injection and an inner electron gun for electron injection in the spherical net into the spherical net and between the spherical net and the anode of the inertial electrostatic confinement fusion apparatus, thereby reducing or eliminating a space charge force generated by deuterium ions, and increasing the deuterium ion density in the spherical net, so that neutron yield and a profit-loss ratio can be increased.