The reform of transmission and distribution (T&D) pricing is a crucial task in achieving the "control the middle, unleash both ends" electricity system reform. A scientifically and reasonably formed transmission and distribution pricing mechanism is of significant importance in creating a fair and orderly electricity market environment and promoting the optimal allocation of electricity resources. In this regard, a transmission pricing method that takes into account the marginal value of lines and spatial?temporal information of users is proposed. Firstly, the cost of the transmission lines is decomposed into two parts: expansion cost reflecting the marginal value of the lines and residual cost, both of which are recovered. Secondly, the expansion cost is devoid of subjective assumptions and is objectively derived based on economic principles. It is determined through the computation of congestion surplus revenue in the electricity spot market clearing under the marginal electricity pricing mechanism at nodes. Next, the residual cost is allocated according to the usage of the transmission lines at each node using the distribution factor method and postage stamp method. Finally, the proposed transmission pricing method is validated for effectiveness using both a 3?node system and the IEEE 30?node system.