Abstract: The wireless power transfer (WPT) technology with relay coils is an effective solution to increase the transmission distance of the system. Based on the parity time (PT) symmetric principle, a WPT system with relay coils can maintain constant output power and constant transfer efficiency when the transmission distance changes. However, in the existing system, the condition of equal distance between adjacent coils must be satisfied, which greatly limits the practicability of the system. Therefore, this paper proposed a three-coil PT symmetric WPT system with variable parameters in the transmitting coil. When the system failed to satisfy the equal distance condition, the values of the variable inductor and capacitor were adjusted to meet the PT symmetric conditions. The paper firstly deduced the output characteristic of the system, then discussed the construction and control method of variable parameters, and finally built an experimental platform for the proposed system. The experimental results show that compared with the existing system, the proposed system could maintain constant power and transfer efficiency when the equal distance condition is not satisfied.