In order to minimize the influence of the magnetic field strength on the magnetic stealth performance of the warship during cable cluster laying, the magnetic field strength and distribution around the medium-voltage DC single-core cable under two typical layouts are simulated and calculated. The optimal cable layout to reduce the magnetic field strength of the cable is determined. Combined with the analysis of the magnetization principle, the result shows that the minimum distance between the cable and the hull structure during cable laying is 300 mm, which can prevent the steel structure from being magnetized and reduces the influence of the cable magnetic field strength on the magnetic stealth performance of warships.