The utility model provides a submarine cable joint preparation purification room equipment system for offshore platform, relates to a cable laying ship. Carry on on purification room that extra large cable connects the preparation generally all arranges the axis of hull, so extra large cable is in cloth cable towing, and it is more to turn, has quality hidden danger. The utility model discloses an anterior central control chamber of hull is located to the hull, the shipping reel of locating the midship with lead cable frame, locate rear portion in the hull cloth cable machine, be used for making the purification room that extra large cable connects and go into the basin, cable frame, the cloth cable machine of leading, purify the room and go into one side that hull fore -and -aft direction axis was all located to the basin. This technical scheme has reduced the extra large cable condition of turning many times, has reduced because of the extra large cable required quantity that turns to the device of turning, has reduced the extra large cable fault probability who turns and appear because of extra large cable, has promoted the convenient operation nature of cloth cable for cloth cable speed.