The invention provides an electric-control type auxiliary tensioning system and method for winding steel wire ropes. The electric-control type auxiliary tensioning system comprises one or more sets of auxiliary tensioning devices, wherein each auxiliary tensioning device comprises a controller, a supporting frame, two electric-control clamping devices and position detecting sensors; the electric-control clamping devices are used for clamping the steel wire ropes when in rope winding and unwinding; the position detecting sensors correspond to each electric-control clamping device and are used for detecting the moving positions of the electric-control clamping devices; the two electric-control clamping devices are arranged on the supporting frame in a sliding manner, and corresponding to each electric-control clamping device, a returning mechanism is respectively arranged; and the controller is respectively and electrically connected with the electric-control clamping devices and the position detecting sensors. The electric-control type auxiliary tensioning system and method provided by the invention have the advantages that when in rope winding or rope unwinding, one electric-control clamping device is started, clamps the steel wire ropes to move, and is stopped when moving to a specific position, then another electric-control clamping device is started and then is stopped when moving to a specific position, another electric-control clamping device is started again and the process is repeated so.