This study is a prospective, multicenter, randomized, open-label, blinded-endpoint trial designed to evaluate the difference in efficacy of Butylphthalide Sodium Chloride Injection treatment initiated early (<3 hours) versus late (3-6 hours) in patients with acute ischemic stroke. The aim is to determine the optimal timing window for neuroprotective therapy.

Inclusion Criteria:

1. Age between 18 and 80 years, gender not specified;
2. Clinically diagnosed with acute ischemic stroke;
3. Stroke onset within 3 hours;
4. NIHSS score at enrollment between 4-25 points, with Item Ia ≤1 point;
5. Pre-stroke mRS score ≤1 point;
6. Participants and their representatives capable and willing to sign an informed consent form.

Exclusion Criteria:

1. Confirmed intracranial hemorrhage within the past 3 months, including intracerebral hemorrhage, intraventricular hemorrhage, subarachnoid hemorrhage, and subdural/epidural hematoma;
2. Known severe hepatic or renal dysfunction or individuals undergoing dialysis for various reasons (severe hepatic dysfunction defined as ALT levels >3 times the upper limit of normal or AST levels >3 times the upper limit of normal; severe renal dysfunction defined as serum creatinine >3.0 mg/dl [265.2 μmol/L] or glomerular filtration rate [GFR] <30 ml/min/1.73m²);
3. Systolic blood pressure <90 mmHg or >220 mmHg;
4. Presence of bradycardia (heart rate below 60 beats per minute) or sick sinus syndrome;
5. History of drug or food allergies, including known allergies to the components of the study medication;
6. Treatment with medications containing Butylphthalide following the onset of the current stroke episode;
7. Congenital or acquired hemorrhagic disorders, coagulation factor deficiencies, thrombocytopenia, or similar conditions;
8. Pregnant or breastfeeding individuals, or those planning to become pregnant within the next 90 days;
9. Severe psychiatric disorders or dementia that preclude understanding of informed consent or compliance with follow-up procedures;
10. Concurrent malignancy or severe systemic disease with a life expectancy of less than 90 days;
11. Participation in another interventional clinical study within the last 30 days before randomization, or currently participating in another interventional clinical study;
12. Any other reason deemed by the investigator as unsuitable for participation in the study.