This study evaluates whether early administration of low-dose aspirin (100mg) at 2 hours post-intravenous thrombolysis, compared to the standard timing of 24 hours, improves functional outcomes in patients with acute ischemic stroke. Intravenous thrombolysis is effective for very early treatment of acute ischemic stroke. However, current guidelines recommend starting antiplatelet therapy 24 hours after thrombolysis to avoid symptomatic intracranial hemorrhage (SICH), a recommendation not based on prospective clinical studies. Early re-occlusion of recanalized arteries due to platelet aggregation occurs in 14-34% of cases and is associated with poor prognosis. The average incidence of SICH is 2.4%, with fatal SICH occurring in only 0.28%. Thus, the impact of re-occlusion on poor prognosis may outweigh the risk of SICH. In this prospective, randomized, open-label trial with blinded endpoint evaluation, participants are assigned to receive aspirin 100mg either at 2 hours (early group) or at 24 hours (standard group) after thrombolysis. The primary outcome is the proportion of patients with a favorable functional outcome, defined as a modified Rankin Scale (mRS) score of 0-2 at 3 months. Safety outcomes include the incidence of SICH and all-cause mortality at 3 months. This study will provide clinical evidence regarding the optimal timing for initiating antiplatelet therapy after thrombolysis in acute ischemic stroke.

Inclusion Criteria:

1. Age range: 18-65 years old
2. Receive rt PA thrombolytic therapy within 3 hours (including 3 hours) of onset
3. Signs of brain dysfunction lasting for more than 1 hour
4. CT imaging excludes cerebral hemorrhage, and there are no imaging changes corresponding to the patient's physical signs

Exclusion Criteria:

1. Age>65 years old
2. Onset time>3 hours
3. Accompanied by consciousness disorders, or NIHSS ≥ 20 points
4. CT shows' high-density shadow of middle cerebral artery '
5. Accompanied by atrial fibrillation or clearly identified as cardioembolic embolism
6. Severe swallowing difficulties, unable to take medication orally
7. Oral anticoagulant medication is currently being taken
8. Accompanied by severe infection or evidence of severe infection
9. Refusal to sign the informed consent form for this study
10. Exclusion criteria for other traditional intravenous thrombolysis