Acute ischemic stroke has a high incidence, ischemic stroke caused by large vessel occlusion is serious and has a poor prognosis, and its triggers in the short term before onset are not clear. The aim of this study was to evaluate the short-term risk of acute ischemic stroke caused by multiple triggers. In this trial, through a case-crossover study design, patients were asked about the exposure to each trigger in the previous year and the exposure during the preictal risk period (the exposure observed during the risk period) for each potential trigger of acute ischemic stroke caused by large vessel occlusion. To evaluate the relative risk of ischemic stroke resulting from exposure to triggers, comparing exposure during the dangerous period with the usual frequency of exposure. Relative risks and corresponding 95% CIs were estimated for past-year exposure and past-year mean exposure (assessed as chronic risk factors) and time to last exposure (assessed as triggers). Scientifically evaluate exposure to a range of potential triggers, including infection, mood, smoking, alcohol consumption, diarrhea and vomiting, extreme temperature changes, and several factors that increase blood pressure and their risk of developing acute ischemic stroke.