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.

Inclusion Criteria:

1. Age between 18 and 65 years.
2. A primary diagnosis of OCD, defined according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-V).
3. Chronic: at least a 3-year history of OCD symptoms with psychosocial dysfunction
4. Severity: a score on the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) of more than 25 or one subscale score of more than 15 ; a score for severity of illness on the Clinical Global Impression (CGI) scale of more than 4.
5. Disability: a score on the Global Assessment Functioning (GAF) scale of less than 45 or a score on Sheehan Disability Scale more than 24.
6. Refractory: a lack of response to drug therapy after adequate administration, defined as more than two types of serotonin reuptake inhibitors at the maximum tolerated dose for more than 12 weeks. Adequate behavior therapy, defined as more than 20 sessions psychotherapy with experienced therapist.
7. OCD medication regimen is stable for at least 4 weeks before enrollment.

Exclusion Criteria:

1. Schizophrenic disorder; bipolar disorder; substance abuse or dependence (except for dependence on nicotine), as assessed with the use of the Mini-International Neuropsychiatric Interview (MINI 6.0.0).
2. Cluster A or B personality disorder according to DSM-IV-TR criteria, as assessed with the use of the Structured Clinical Interview II.
3. A current severe major depressive episode, determined according to DSM-V criteria (as assessed with the use of the MINI 6.0.0) and defined by the Hamilton Depression Rating Scale-17 (HAMD) score of more than 20 and a risk of suicide.
4. Abnormal cognitive status (measured by MoCA), abnormal findings on functional magnetic resonance imaging (MRI) of the brain, or contraindications to surgery or anesthesia.