A method of constructing a distribution line using an extra-high voltage neutral line combined with an overhead earth wire having a separate installation structure of the extra-high voltage neutral line and a low-voltage neutral line, in which a distribution line includes a power line provided at an upper part of an electric pole through a crossarm having an insulator, an overhead earth wire provided at an upper end of the electric pole, a transformer provided below the power line and positioned at a low-voltage jointed area, a low-voltage neutral line combined with an extra-high voltage neutral line provided below the transformer in parallel with the power line, and a low-voltage line provided at a position corresponding to the low-voltage jointed area, the method comprising: separating the low-voltage neutral line and the extra-high voltage neutral line, configuring the overhead earth wire and the extra-high voltage neutral line into an integrated overhead earth wire and extra-high voltage neutral line and installing the integrated overhead earth wire and extra-high voltage neutral line on a top end of the electric pole by using a multi-cap; connecting the transformer and the integrated overhead earth wire and extra-high voltage neutral line by installing the low-voltage neutral line and the low-voltage line so that the low-voltage neutral line and the low-voltage line are connected to a low-voltage load part of the electric pole, in which the transformer is installed, below the transformer in the low-voltage jointed area such that a low-voltage load current is prevented from flowing through the integrated overhead earth wire and extra-high voltage neutral line; and installing a ground at the electric pole, in which the transformer of the low-voltage jointed area connected to the integrated overhead earth wire and extra-high voltage neutral line is installed, and at the electric pole in which an arrester or a switch is installed and ground-connecting the integrated overhead earth wire and extra-high voltage neutral line to the remaining electric pole so that the ground is installed to every electric pole. separating the low-voltage neutral line and the extra-high voltage neutral line, configuring the overhead earth wire and the extra-high voltage neutral line into an integrated overhead earth wire and extra-high voltage neutral line and installing the integrated overhead earth wire and extra-high voltage neutral line on a top end of the electric pole by using a multi-cap; connecting the transformer and the integrated overhead earth wire and extra-high voltage neutral line by installing the low-voltage neutral line and the low-voltage line so that the low-voltage neutral line and the low-voltage line are connected to a low-voltage load part of the electric pole, in which the transformer is installed, below the transformer in the low-voltage jointed area such that a low-voltage load current is prevented from flowing through the integrated overhead earth wire and extra-high voltage neutral line; and installing a ground at the electric pole, in which the transformer of the low-voltage jointed area connected to the integrated overhead earth wire and extra-high voltage neutral line is installed, and at the electric pole in which an arrester or a switch is installed and ground-connecting the integrated overhead earth wire and extra-high voltage neutral line to the remaining electric pole so that the ground is installed to every electric pole.