Objective To analyze the clinical characteristics and influencing factors for prognosis of patients with severe fever with thrombocytopenia syndrome (SFTS) in Dalian, and provide reference for early treatment to reduce mortality. Methods 112 cases of SFTS in Dalian Center for Disease Control and Prevention from 2018 to 2020 were collected, including 79 survival cases and 33 death cases, clinical characteristics, laboratory indicators and prognostic factors of SFTS patients in survival group and death group were analyzed. Results A total of 112 patients were included in analysis, mortality was 29.5%. There were significant difference in age, diabetes mellitus, hypertension, atrial fibrillation, and length of hospital stay between survival group and death group (all P < 0.05). In clinical symptoms, the proportion of early neurological symptoms and bleeding in death group was higher than that in survival group; in laboratory indicators, including calcium ion, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, creatinine, urea nitrogen, prothrombin time, prothrombin activity, albumin, platelet, C-reactive protein, and virus load, difference between death group and survival group were all statistically significant (all P < 0.05). Multivariate logistic regression analysis showed that viral load, neurological symptoms, bleeding and creatine kinase>170 U/L can be used to predict the prognosis of SFTS patients. Conclusion The mortality of SFTS patients in Dalian is high, viral load, early neurological manifestations, bleeding and early creatine kinase >170 U/L can be used as prognostic indicators. Whether the cause of high mortality of SFTS patients in Dalian is related to the difference of virus strain and virulence, as well as clinical treatment needs to be further studied.