Decompression illness (DCI) has been deemed a rare clinical entity in different diver populations. The incidence of DCI varies from 0.010% to 0.095% per dive. The DCI is a collective term including two disorders. The first one is caused by evolution of bubbles from dissolved inert gas; the second one is caused by introduction of air to the systemic circulation by pulmonary barotrauma. The gold standard treatment for DCI is recompression in a hyperbaric chamber with administration of hyperbaric oxygen during the treatment. We report a case of a 46-year-old technical diver complained decrease motor and sensory function of lower limbs 50 minutes after diving mission had been completed. He had received first aid 100% oxygen and sought medical attention right after the accident. After hyperbaric chamber treatment, the lower limb muscle power recovered from 2/5 to 3/5. He was discharged from hospital after rehabilitation for 3 months when he could walk by himself. After follow up for 12 years, his lower limb muscle power had no improvement while he complained increase of walking instability. The MRI scan discover thoracic spinal cord atrophy. The side effect of spinal cord atrophy induced by DCI has not been reported before.