Within an one-dimensional tight-binding Su-Schreiffer-Heeger model, we investigate the effect of interchain coupling on inelastic scattering of oppositely charged polarons in conjugated polymer by using a nonadiabatic evolution method. It is found that the yield of the neutral exciton depends sensitively on the interchain coupling. The yield of the neutral exciton increases with the enhancement of overlapping which can make the wave functions of oppositely charged polarons more largely overlapped. The formation yield of excitons also increases with the number of overlapping sites increasing to its maximum value, where the length of overlapping sites is almost of the same order of magnitude as the width of the polaron, the reason is that the number of overlapping sites can affect the overlap of oppositely charged polaron wave functions. In turn, the charge transfer between them depends on the overlap of their wave functions. Therefore, when the size of overlapping sites is almost of the same order of magnitude as the width of the polaron, their wave functions have a largest overlap, thereby making charge transfer more easily. So the yield of excitons has the largest value.