The problems of the coordination strategy of MMC-HVDC transmission system connecting with weak AC system and AC side reclosing deserves further study. The voltage and current variation characteristic during AC line reclosing is studied in this paper, with Chongqing-Hubei back to back MMC-HVDC project as an example. Combined with the fault ride through control logic, the feasibility of the control strategy after the line disconnection is analyzed. The analysis results show that after the line disconnection, the positive sequence controller and the negative sequence controller cannot be completely decoupled, which causes the control system to be unstable. The disconnected line may overvoltage and when the fault is recovered, the overcurrent may occur in bridge arm. Therefore, when single line with MMC-HVDC operates and the break fault occurs, the power transmission of the straight line should be minimized during the fault time, or the reclosing function of the AC line should not be enabled. This work is supported by National Key Research and Development Program of China (No. B3441416K012) “Complete Design and System Integration of Flexible DC Engineering and its Application in Engineering Demonstration”.