There are few lightning protection measures available for 10 kV overhead lines. In view of their characteristics of being mostly subjected to induced lightning and short circuit trips between phases, single-phase installation of parallel gaps can be used to improve the lightning resistance level. But the exising single-phase different-line installation mode cannot improve the lightning resistance level when short-circuit happens between two phases on different pole bases. Therefore, this paper proposes a new single-phase same-line installation mode, that is to install the parallel gap on only one phase of the same line. According to the characteristics of the 10 kV overhead line, the principle of the installation mode to improve the lightning resistance level is analyzed, and the 10 kV overhead line model is established by ATP-EMTP. Simulation results show that when the single-phase same-line installation of the parallel gap is applied to the 10 kV overhead line, the lightning resistance levels under induced lightning overvoltage and overvoltage by lightning striking at cross-arm, are increased by 84.87% and 103.53% respectively cwompared with those without parallel gap; Comparing with the single-phase different-line installation mode, the increase is 62.26% and 78.35% respectively. However, the lightning resistance level under the overvoltage of the lightning striking on line does not incease significantly. Through experiments and calculations, the optimal distance range of the single-phase same-line installation of parallel gap is 80.01~106.31 mm. Single-phase same-line installation of parallel gap can significantly improve the lightning resistance level of the distribution line when lightning is induced and the cross arm of the tower is struck by lightning, effectively protect the line insulators, and improve the operational reliability of the distribution network.