In order to solve the problem of uneven distribution of traffic and traffic congestion in the toll plaza of the smart expressway, the measure of opening tidal lanes was proposed under the premise of certain spatial resources, and the optimal number of open lanes was explored. Taking the Xiong′an North mainline toll station of Jingxiong Smart Expressway as the research object, the tidal traffic flow characteristics of the lanes was analyzed and the feasibility of setting tidal lanes was demonstrated; The tidal coefficients of 06,07,07,08 and 09 were selected, and the traffic volume was divided into six grades of A—F, and the VISSIM toll station simulation model was established; Taking the morning peak of the toll station as an example, the simulation results such as traffic volume of each simulation scheme were analyzed to determine the number of tidal lanes to be opened under different traffic flow states. The results show that with the toll station exit as the main traffic flow direction, it is appropriate to open one tidal lane when the tidal coefficient is 07 and the traffic volume is C—F level and the tidal coefficient is 09 and the traffic volume is B level; When the tidal coefficient is 08 and 09, 2 and 3 tidal lanes are opened under C—F traffic volume respectively; in other cases, no tidal lane is opened. Relying on the Xiong′an North mainline toll station of the Jingxiong Smart Expressway with commuting function, studying the optimal number of opening tidal lanes can provide a reference for the regulation and control of the entrance and exit lanes of smart expressway, and has practical significance for improving its traffic capacity and efficiency.