Refractory obsessive-compulsive disorder (OCD) is a disabling condition. Deep brain stimulation (DBS) of ventral capsule/ventral striatum(VC/VS) is potentially the most effective treatment for refractory OCD. However, the affecting area of traditional electrodes is limited and not specific to VC/VS. The investigators designed a novel electrode, 2 mental contacts(3mm contact-2mm space-3 mm contact) could be implanted in ventral striatum and the other upper 2 contacts(4mm space-3mm contact-4mm space-3mm contact)that can be implanted in ventral capsule simultaneously, which the investigators believe will be more effective due to better compatibly with anatomical features of target area. This trial is to evaluate the effectiveness and safety of this approach.