Abstract: The deep charge effect has emerged as a primary space environmental factor posing significant threats to the orbital safety of satellites. To accurately simulate the characteristics of deep discharge pulses and evaluate the resistance of spacecraft components against the deep discharge, researchers have adopted an RLC circuit to optimize the parameters of discharge pulses generated by commercial ESD generators, including waveform, current amplitude, and duration. This approach has enabled the simulation of pulses exhibiting oscillatory attenuation, microsecond-scale durations, and small current amplitudes. By ensuring that the simulated pulses align with the characteristics of deep discharge while offering the benefits of excellent reproducibility and adjustable discharge parameters, a simulation testing methodology tailored for quantitative investigation of deep discharge-induced damage to electronic devices has been established. MOS devices have been tested using this methodology, and their damage mechanisms have been analyzed. The results indicate that when a simulated pulse is injected into the gate of a MOS device, an interference signal is generated. When the pulse current amplitude is low, the device can swiftly recover its signal output. However, when the current increases to 9 A, the simulated pulse triggers a breakdown of the internal insulation layer, leading to irreversible “hard damage” to the MOS device. Furthermore, research has shown that even when the discharge current falls below the damage threshold, the simulated pulse can still cause insulation damage, resulting in an increased leakage current between the drain and source of the MOS device. This damage can accumulate over multiple discharge instances until the insulation layer is completely compromised, ultimately causing device failure. This research holds significant guidance and application value for evaluating satellite deep electrification effects and designing protective measures. It provides a comprehensive understanding of the damage mechanisms caused by deep discharge pulses and offers insights into the development of more resilient spacecraft components capable of withstanding such extreme space environmental conditions.