This study investigates the effects of rt-PA thrombolytic therapy at varying times on neurological function and complications in acute cerebral infarction (ACI) patients. A total of 120 ACI patients admitted between August 2019 and July 2021 were divided into three groups based on the timing of rt-PA treatment: <3h (40 patients), 3-4.5h (55 patients), and >4.5h (25 patients). All received standard treatment and rt-PA IV thrombolysis. Key comparisons included cerebral oxygen metabolism, oxidative stress, neural markers, hemodynamics, coagulation function, NIHSS scores, ADL, clinical efficacy and complications. Results showed that 48 hours post-treatment, SjvO2 levels were significantly higher in the <3h and 3-4.5h groups compared to the >4.5h group. SOD levels were also higher in the earlier groups, while MDA levels were lower. Three months after treatment, NIHSS scores were significantly lower and ADL scores higher in the <3h and 3-4.5h groups, with lower complication rates. Efficacy was similar within 3 hours and 3-4.5 hours, but complications increased significantly after 4.5 hours.