The invention relates to a vertical well large-diameter cable simultaneous removal device and a construction method thereof. The removal device comprises a wellhead frame, a cable lifting device, an operation platform, a cable fixing device and a cable take-up device; the wellhead frame is supported above a wellhead; the cable lifting device includes a first pull cable and a shaft sinking winch; one end of the first pull cable is connected with the shaft sinking winch, and the other end of the first pull cable winds over the top of the wellhead frame and extends into a vertical shaft; the operation platform is suspended in the vertical shaft through a second pull cable; the cable fixing device comprises a set of cable clamps; each cable clamp includes two cable clamping plate units and connecting components; a set of vertical clamping slots is formed in the plate surface of the cable clamping plate unit at intervals; the two cable clamping plate units are vertically arranged at two sides of cables to be removed and the first pull cable; and the two cable clamping plate units are correspondingly connected together through the connecting components. With the vertical well large-diameter cable simultaneous removal device and the construction method thereof of the invention adopted, technical problems such as low cable construction efficiency in dismantling cables one by one, laborconsumption and time consumption during rotation tightening in processing the cables and proneness to damaging the protective layers of the cables of a traditional construction method can be solved.