The invention discloses a synchronous computer controller device for overall tension and a construction method. The device comprises a mechanical system, a hydraulic system and a control system, wherein the mechanical system comprises a tensioned space cable structure, a steel tension cable and a tension tool, wherein the steel tension cable is connected with the tensioned space cable structure and the tension tool respectively; the hydraulic system comprises a hydraulic pump station, a hydraulic jack group and various hydraulic valves; the hydraulic jacks are connected with the hydraulic pump station; tensile force is applied to the tension tool; the control system comprises a computer and a main control cabinet; the main control cabinet is connected with a computer, the hydraulic systemand the mechanical system respectively; and the main control cabinet comprises a communication control board, a PLC (Programmable Logic Controller), a phase sequence control relay, various interface boards, a transmission line and a remote monitoring sensor. The device has the advantages of simple manufacturing process, economical efficiency, reasonable manufacturing cost, easiness and convenience for operating, high synchronous control accuracy and the like.