Objective: To analyze the application value of platelet aggregation combined with thromboelastography in detection after thrombolysis for cerebral infarction. Methods: Eighty-four patients with cerebral infarction who underwent thrombolysis in the hospital from January 2021 to June 2024 were selected, and divided into the good prognosis group and the poor prognosis group according to the prognosis. The two groups were compared in terms of postoperative early platelet aggregation [arachidonic acid induced maximum platelet aggregation rate (AA-MAR) and adenosine diphosphate induced maximum platelet aggregation rate (ADP-MAR)] and thromboelastography parameters [coagulation reaction time (R), coagulation time (K), formation rate of blood clot (Angle), maximum thrombus amplitude (MA) and coagulation index (CI)]. The relationship between above parameters and the prognosis of cerebral infarction after thrombolysis was analyzed. The receiver operating characteristic (ROC) curve was used to analyze the predictive value of platelet aggregation combined with thromboelastography parameters for poor prognosis of cerebral infarction after thrombolysis. Results: Compared with the good prognosis group, AA-MAR, ADP-MAR, Angle, MA and CI were significantly higher, and R and K were significantly lower in the poor prognosis group (P<0.05). Logistic regression analysis showed that AA-MAR, ADP-MAR, R, and K were independent factors influencing the prognosis of cerebral infarction after thrombolysis (P<0.05). The area under the ROC curve of platelet aggregation combined with thromboelastography parameters for predicting poor prognosis of cerebral infarction after thrombolysis was 0.961. Conclusion: Early platelet aggregation and thromboelastography in patients with cerebral infarction after thrombolysis both affect the prognosis. Combined detection of quantitative parameters has high prognostic value.