Abstract: The paper presents a time-domain integration method for transient analysis of multiconductor transmission lines (MTL) in order to solve difference oscillation problems caused by the finite-difference time domain (FDTD) in the analysis of transient analysis of nonuniform lossy MTL. In modeling unequal length nonuniform lossy MTL, this method need not decouple transmission lines and is directly used in solving unequal length nonuniform lossy MTL system. It firstly discretizes the spatial derivatives in the electricwave equations by differences, and then calculates the time integral of the time derivatives by Trapezoid integral calculus method. Finally, a time-domain integration method is obtained. The method is used to calculate and analyze the models of unequal length nonuniform lossy MTL. The method is simulated by the models of MTL with linear loads and nonlinear loads. The results of simulation are shown that the presented method is effective.