Objective:To analyze the effect of modified Banxia Baizhu Tianma Decoction combined with Nimodipine on cognitive dysfunction and changes on cerebral blood flows of the patients with chronic cerebral insufficiency (CCCI).Methods:A total of 91 patients with CCCI who received treatment in our hospital from March 2019 to March 2020 were selected and divided into the treatment group ( n=46) and the control group ( n=45), according to random number table method. The control group was treated with Nimodipine oral treatment, and the treatment group was treated with modified Banxia Baizhu Tianma Decoction on the basis of the control group treatment. Both groups were treated for 2 weeks. The Traditional Chinese Medicine (TCM) syndrome scores were performed before and after treatment, and transcranial Doppler ultrasound was used to detect the average blood flow of bilateral vertebral arteries (VA), basilar arteries (BA), internal carotid arteries (ICA) and middle cerebral arteries (MCA). The whole blood viscosity high shear (HS), whole blood low shear (LS), plasma viscosity (PV), fibrinogen (FIB) and hematocrit (HCT) were detected by automatic blood rheometerusing. The Montreal Cognitive Assessment Scale (MoCA) was used to assess the degree of cognitive impairment and evaluate the clinical efficacy. Results:The total effective rate was 91.3% (42/46) in the treatment group and 73.3% (33/45) in the control group, with a statistically significant difference between the two groups ( χ2=5.07, P=0.024). The scores of dizziness, headache, forgetfulness, insomnia and total scores in the treatment group were significantly lower than those in the control group after treatment ( t values were 8.59, 7.79, 3.92, 4.11, 5.01, all Ps<0.01), and the MoCA score (25.13±2.16 vs. 23.88±2.70; t=2.44, P=0.017) in the treatment group significantly higher than that in the control group. After treatment, VA [(35.49±4.08) cm/s vs. (32.17±4.25) cm/s, t=3.80], BA [(36.99±3.79) cm/s vs. (33.76±4.12) cm/s, t=3.89], ICA [(62.49±5.07) cm/s vs. (58.91±5.31) cm/s, t=3.29], MCA [(70.09±5.04) cm/s vs. (67.12±5.85) cm/s, t=2.60] in the treatment group was significantly higher than those in the control group ( P<0.01). After treatment, the levels of HS, LS, PV, Fg, and HCT in the treatment group were significantly lower than those in the control group ( t values were 2.37, 4.35, 2.23, 2.42, 2.20, P<0.05 or P<0.01). Conclusion:Modified Banxia Baizhu Tianma Decoction combined with Nimodipine tablets can relieve the clinical symptoms of CCCI patients, improve blood flow velocity, blood rheology level and cognitive function, and improve clinical efficacy.