Objective To investigate the relation between the expression levels of serum 8-Hydroxydeoxyguanine （8-OHdG）， macrophage migration inhibitory factor （MIF） and the cognitive function in patients with schizophrenia. Methods A total of 50 patients with schizophrenia admitted to the Mental Health Center of Shiyan Taihe Hospital from September 2019 to September 2020 were selected as the trail group. At the same time， 50 health people who underwent physical examination in the outpatient clinic of Shiyan Taihe Hospital were selected as the control group. In both groups， fasting venous blood samples were collected from the patients， and the levels of 8-OHdG and MIF in the serum of the two groups were tested by enzyme-linked immunosorbent assay （ELISA）. MATRICS Consensus Cognitive Battery （MCCB） was used to evaluate the cognitive function of the two groups. The clinical symptoms of the two groups were evaluated using the Positive and Negative Symptom Scale （PANSS）. Results The level of serum 8-OHdG in the trail group （59.33±10.58） ng/L was significantly higher than that of the control group （26.17±8.45） ng/L （t=3.692， P=0.003）； the expression level of MIF showed the same pattern with 8-OHdG （t=2.451， P=0.018）， and the concentration of 8-OHdG and MIF in the serum of the trail group was significantly positively correlated （r=0.854， P=0.003）. In addition， the cognitive function of the trail group was significantly lower than that of the control group. The level of serum 8-OHdG in the trail group was positively correlated with the total score of PANSS （r=0.549， P=0.015） and the positive symptom score （r=0.476， P=0.032）. However， the level of MIF was positively correlated with the total score of PANSS （r=0.418， P=0.038） and negative symptom score （r=0.196， P=0.057） . The expression levels of serum 8-OHdG （r=0.673， P=0.005） and MIF （r=0.421， P=0.028） were positively correlated with working and memory abilities in the MCCB cognitive function test. Conclusions It can be seen that the expression levels of serum 8-OHdG and MIF in patients with schizophrenia are significantly increased， and there is a strong correlation between the clinical symptoms and cognitive dysfunction of the patients.