The invention provides an ECPT-based electric energy and signal circuit separated parallel transmission system and a parameter design method. A signal transmission channel composed of a pair of signal transmission pole plates and a signal detection resistor is added on the basis of an ECPT system achieving double-side LC compensation, and the parameter design method is proposed accordingly. According to the system and the method, an additional impedance isolating circuit does not need to be added for reducing electric energy crosstalk, the low-crosstalk and low-attenuation signal transmission channel is constructed through the self impedance characteristic, stable, reliable and parallel transmission of signals is achieved through the channel on the premise that the electric energy transmission power is guaranteed, and meanwhile the channel complexity and the integral system cost are reduced. In addition, the effectiveness of the method is verified through simulation and experiments, and electric energy and signal parallel transmission in the Baud rate range of 1.2 kbps to 115.2 kbps is achieved through built system experiment devices.