With the growth of the economy, the demand for electricity increases daily, and with the strain on power transmission corridors, the construction of multi-circuit transmission lines on the same tower is becoming increasingly common. This paper simplifies the zero-sequence parameters based on the six-circuit transmission line of the same voltage level, under the premise of symmetric tower structure, reducing the difficulty of solving the transmission line equation. Correspondingly, a measurement method is proposed, synchronously measuring the zero-sequence voltage and current values at the beginning and end of the line, then substituting them into the calculation formula derived in this paper to solve all the required zero-sequence parameters of the line. The parameter measurement theory and method proposed in this paper are verified and analyzed using software, compared with the improved traditional methods, the measurement accuracy is improved, the measurement efficiency is increased, which is more beneficial to practical engineering applications.