In the single-wire power transfer (SWPT) system, electrical energy can be transmitted efficiently through only one wire over long distances. In this paper, under the structure of multilayer Tesla's coil, the effect of the number of turns of the low-voltage coil (LVC) on the transmission performance of the system at different transmission distances is studied. Firstly, a circuit model of the SWPT system is built. Then, the effects of changing the number of turns of the LVC on various circuit characteristics such as input current, voltage gain and transmission efficiency are analyzed through the circuit model. Finally, at the 50 m experimental site, the power of 500 W can be deliveredwith an efficiency of 89.8% in the system with fewer LVC turns. After the number of turns is increased, the input current is reduced and the efficiency is improved. The SWPT system can transmit 5 kW at 5 km.