Inclusion Criteria:  1) Age≥18 years, regardless of sex; 2) Patients with a clinically definite diagnosis of acute ischemic stroke and undergo intravenous thrombolysis with alteplase; 3) Baseline NIHSS >= 4, and <= 24; 4) Baseline mRS 0-1; 5) Signed and dated informed consent is obtained;  Exclusion Criteria:  1) Patients who undergo endovascular treatment. 2) Patients who have the contraindication of intravenous thrombolysis with alteplase. 3) The patients who have the contraindication of remote ischemic conditioning treatment, such as severe soft tissue injury, fracture or vascular injury in the upper limb. Acute or subacute venous thrombosis, arterial occlusive disease, subclavian steal syndrome, etc. 4) Pregnant or lactating women. 5) Previous remote ischemic conditioning therapy or similar treatment; 6) Severe hepatic and renal dysfunction. 7) Patients with a life expectancy of less than 3 months or patients unable to complete the study for other reasons. 8) Unwilling to be followed up or treated for poor compliance. 9) He/She is participating in other clinical research or has participated in other clinical research or has participated in this study within 3 months prior to admission. 10) Other conditions that the researchers think are not suitable for the group.