There are many factors impacting the unbalanced tensile force of the transmission line. To the micro-terrain, the factors including long-span, big altitude difference and large distance difference. Generally speaking, single factor from micro-terrain will not have destructive impact on the transmission line, while the combination of various factors does. In this paper, all possible factors of micro-terrain are assembled, the computation software for unbalanced tensile force is applied and the computation results are achieved for all possible cases. The impact pattern are summarized which can be referenced for future transmission line design and transforming.