The invention relates to a safety lock system suitable for an offshore converter station valve hall, and aims to provide the safe and reliable safety lock system suitable for the offshore convertor station valve hall. According to the technical scheme, the safety lock system suitable for the offshore convertor station valve hall is characterized by being provided with a host device, an alarm device, a door lock and an electromagnetic lock installed on a valve hall door, and a key lock arranged outside the valve hall, wherein a personnel entry and exit counting device used for recording data ofthe entry and exit of personnel is arranged corresponding to the valve hall; and a valve hall key is locked on the key lock, the key lock is provided with an unlocking knob which is controlled to beunlocked through the host device, and when receiving signals of the valve shutdown and ground cutter closing of a converter station control system, the host device controls the unlocking knob to be unlocked. The safety lock system is suitable for the field of safety guarantee.