At present, a quantitative research on the mechanisms and laws of the application of resonant neutral grounding (RNG) to shipboard medium voltage (MV) power grid is scarce. Based on the theoretical analysis of single-phase to ground fault for shipboard MV power grid, combining with transient simulation, the paper studies the impact of damping ratio and tuning degree of arc-suppression coil on arc-extinct recovery voltage, re-strike overvoltage, neutral displacement voltage and fault current. The effects of generator frequency offset and arc angle are also discussed. The results show that increasing the damping ratio will decrease the arc-extinct voltage recovery overshoot, thereby reducing re-strike overvoltage, but will also increase fault current. While increasing tuning degree will increase the arc-extinct voltage recovery overshoot, and possibly cause greater re-strike overvoltage, so the tuning degree should be appropriate to restrict the fault current. In addition, the generator frequency offsets can also lead to greater transient overvoltage.