This paper presents an efficient evaluation method for multiconductor transmission lines with random translation over an infinite and perfectly conducting ground under a plane wave. Based on the assumption of small translation quantity, the equations for the estimation of average induced voltage, induced voltage variation, and the probability distribution of the voltage variation are derived. The average induced voltages and the probability distribution of the voltage variation estimated by the proposed method are in a good agreement with those via the Monte Carlo method but the proposed method is more efficient. The relative sensitivity of the induced voltage to the height approximately equals the inverse of the line height, which can be applied to evaluate the influence induced by the random translation of the line quickly, especially in the low frequency range.Index Terms-Electromagnetic interference, induced voltage, randomness, statistical analysis, and transmission line.