Abstract: In order to improve the transmission capacity of the cable and facilitate the construction, multiple single-core cables are connected in parallel for each phase of the buried cable on the low-voltage side of the box-type transformer in the wind farm. Due to the non-standard design and on-site cable laying construction, the mutual inductance reactance of each cable in the same phase is different, and the current is unbalanced, resulting in over-temperature of some cables and possible cable breakdown.In this paper, the reasons for cable overheating on the low voltage side of the transformer box are analyzed, and a reasonable cable distribution scheme is adopted to ensure the basic balance of the current of each cable, completely solve the problem of cable high temperature, and provide a reference for similar defects.