Abstract: Power supply quality not only affects the normal consumption of residents, but also affects the stable operation of power distribution grids. The continuous social development brings about increasing equipment load, and the low voltage problem is particularly prominent under the influence of single radiation, long distance and heavy load of the lines. To this end, the causes of low voltage in rural distribution substation areas and the treatment scheme are analyzed, starting with the introduction of a quick calculation method of voltage loss for low-voltage lines and followed by the definition of low voltage. Taking Fujian Rural Power Network as an example, the causes of low voltage problem in the rural distribution substation area are analyzed, and the corresponding low voltage treatment measures are proposed, from which the effectiveness of the countermeasures are verified via typical cases.