Our three-step screening system uses commonly used clinical and laboratory parameters to effectively identify patients who may be at high risk of HLH, conduct etiology screening early for patients who meet the diagnostic criteria for HLH, and guide standardized treatment. Therefore, this study proposes to establish a highly accurate and convenient hemophagocytic early warning system to improve the early diagnosis of patients with hemophagocytic syndrome and identify suspected HLH patients early. Etiology screening is performed on patients who meet the diagnostic criteria for HLH, high-risk predisposing factors are identified, and precise treatment is guided, thereby improving the success rate of patient treatment and improving the quality of life.