The invention discloses a system and method for a continuous beam flexible pier to resist horizontal force. The system comprises a tension end, an anchoring end and a steel stranded wire. The tension end comprises a first anchor seat arranged on a spliced beam section at the back through a first steel bar, the first anchor seat is provided with a horizontally arranged jack, the anchoring end comprises an anchor plate and a second anchor seat arranged on a front flexible pier top segment beam through a second steel bar, the tension end is connected with the anchoring end through the steel stranded wire, one end of the steel stranded wire penetrates through the jack through the first anchor seat, and the other end of the steel stranded wire is fixed on the second anchor seat through the anchor plate. According to the system and method for the continuous beam flexible pier to resist the horizontal force, movement and displacement of the flexible pier in the segment beam erecting process can be reduced through an opposite-pull device, and structural safety of a flexible pier body is guaranteed.