【Objective】 To investigate the causes of abnormal decrease in maximum amplitude(MA) of thromboelastography(TEG) and its effect on prognosis by monitoring the changes of coagulation-related indexes in emergency trauma patients. 【Methods】 A total of 319 cases of trauma patients admitted to our hospital from September 2020 to September 2023 were retrospectively analyzed, and the coagulation-related indexes of 0 h and 24 h after admission were observed. According to the MA results, they were divided into normal MA group(>50 mm) and reduced MA group(≤50 mm) to compare the hemoglobin(Hb), platelets count(Plt), activated partial thromboplastin time(APTT), prothrombin time(PT), fibrinogen(Fib), thrombin time(TT), D-dimer(D-D), coagulation reaction time(R), clot formation kinetics(Angle), 30 min clot dissolution rate(Ly30), MA, thrombine-antithrombin complex(TAT) and plasminase-α2 plasminase inhibitor complex(PIC). The correlation between MA and fibrinolysis indexes in 319 trauma patients was analyzed. According to whether tranexamic acid(TXA) was used, the reduced MA group was divided into a TXA group and a non-drug group. The differences in the change of the above coagulation-related indexes, mortality rate and changes in blood product dosage were compared between the two groups. 【Results】 Compared with the normal MA group, Hb, Plt, Fib, diastolic blood pressure and GCS scores decreased, while heart rate, ISS score and mortality increased significantly in the reduced MA group(P<0.05). The R, PT and TT were prolonged significantly(P<0.05), and PIC and D-D increased significantly(P<0.05) in the reduced MA group. Correlation analysis found that MA had no correlation with Ly30, TAT and APTT, but was correlated with Angle(r=0.803), Plt(r=0.544), Fib(r=0.581), PIC(r=-0.443) and D-D(r=-0.343). Compared with the non-drug group, the change of Angle, MA and FIB in the TXA group increased significantly(P<0.05), while the change of PIC decreased(P<0.05). Cryoprecipitate and platelet transfusion in the TXA group reduced significantly(P<0.05), and red blood cell transfusion had a decreasing trend, but the difference was not significant(P>0.05). The mortality rate in the TXA group was reduced significantly(P<0.05). 【Conclusion】 Hyperfibrinolysis may be an important factor in the abnormal decrease of MA in emergency trauma patients. Treatment with TXA can improve its effect on MA, and reduce the transfusion of blood products and the patient mortality.