The invention discloses an optimized configuration method for position of flexible direct current interconnected device in transmission cross section. The method firstly calculates an initial transmission capacity P0 of the transmission section without the flexible DC interconnection device. After the flexible DC interconnection device is arranged at the AC line lk, , the transmission capacity ofan AC cross section of the transmission cross section, the transmission power limit of the flexible DC interconnection device, and transmission capacity of the transmission section are calculated. Finally, the transmission capacity lifting coefficient of the whole power transmission cross section after each AC line is equipped with the flexible DC interconnected device is calculated according to aformula as described and P0. The lifting coefficients are compared and the AC line where the maximum coefficient is located is selected as the optimal location of the flexible DC interconnection device in the transmission section. The invention can accurately determine the optimal configuration line of the flexible DC interconnecting device, so as to maximize the transmission capacity of the transmission section.