In order to solve the problems that after the operation of power spot market, it is difficult to determine the transmission price of the dedicated transmission projects in accordance with the original method, and that the current transmission pricing mechanism may affect the competitive efficiency of power spot market, the optimization model of twopart transmission price for dedicated transmission projects oriented to power spot market is put forward. Firstly, this paper analyzes the inadaptability of transmission pricing mechanism of China's current inter-regional/provincial dedicated projects, which are mainly based on the function of transmission, in the environment of power spot market, and explains its adverse impacts in terms of fair sharing of the recovery risk of the permitted revenues of the dedicated projects, as well as the promotion of effective competition in the power spot market. Then, the impact of the power transmission price for dedicated transmission projects on power spot market is analyzed, and the optimisation model for two-part transmission price based on the one-dimensional search algorithm and the joint economic dispatch model of multi-period energy and reverse is designed and established, so as to determine the critical point of capacity price recovery of permitted revenues from dedicated transmission projects in two-part transmission price. Finally, the validity of the model is verified by case simulation, and the key factors affecting the transmission price structure are analyzed.