Objective To investigate the efficacy of breviscapine combined with alteplase in the treatment of acute cerebral infarction beyond thrombolytic time window. Methods A total of 82 patients with acute cerebral infarction beyond thrombolytic time window were randomly divided into experimental group (40 cases) and control group (42 cases). The control group was treated with alteplase, and the experimental group was treated with breviscapine on the basis of the control group. Before and 2 weeks after treatment, the degree of neurological deficit [National Institutes of Health Stroke Scale (NIHSS)], regional tissue perfusion of cerebral infarction [relative cerebral blood volume (rCBV), cerebral blood flow (CBF)], hemorheological indexes [high shear whole blood viscosity (HSBV), low shear whole blood viscosity (LSBV), plasma viscosity (PV), hematocrit (HCT)], the indexes of oxidative stress [malondialdehyde (MDA) and superoxide dismutase (SOD)] were compared between the two groups. Results After 2 weeks of treatment, NIHSS score, HBSV, LSBV, PV, HCT and MDA levels of the two groups were significantly lower than those before treatment, and those of the experimental group were significantly lower than the control group at the same time (P＜0.05). The rCBV, CBF and SOD levels of the two groups were significantly higher than those before treatment, while those of the experimental group was significantly higher than the control group (P＜0.05). Conclusions Breviscapine combined with alteplase in the treatment of acute cerebral infarction beyond thrombolytic time window had good therapeutic effect, which was beneficial to improve the degree of neurological deficit, increase the perfusion volume of infarcted area, improve the cerebral blood flow of patients, and was beneficial to the prognosis and rehabilitation.