This study compares the diagnostic value of conventional coagulation tests (CCTs) and thromboelastography (TEG) for high blood coagulation states in advanced malignant tumors and to explore the diagnostic efficacy of their combination. In this study, 120 patients with advanced malignancy were divided into hypercoagulable state (n = 62) and non-hypercoagulable state (n = 58) groups. Traditional coagulation tests or CCTs (including prothrombin time, activated partial thromboplastin time, international normalized ratio, fibrinogen, D-dimer, and platelet count) were conducted. Simultaneously, TEG parameters, such as kinetic time, reaction time, clotting angle, maximum amplitude, and coagulation index, were assessed. Baseline demographic and pathological data were also collected. The role of conventional coagulation indicators, TEG indicators, and their combination in diagnosing high blood coagulation states was explored. The diagnostic efficiency was evaluated by constructing curves and calculating the area under the curve (AUC). Among 120 patients with advanced malignancy, 51.67% (62/120) had a hypercoagulable state. Among CCTs, activated partial thromboplastin time, D-dimer, and platelet count were associated with a hypercoagulable state, whereas no significant differences were found in other indicators. Among TEG parameters, maximum amplitude, reaction time, and clotting angle were associated with a hypercoagulable state, whereas kinetic time and coagulation index were not significantly different. The combined use of CCTs and TEG parameters was more effective in diagnosing hypercoagulable states than either test alone. The AUC values for the diagnostic efficacy of the CCTs, TEG, and TEG combined with CCTs for the diagnosis of hypercoagulable transitions in blood were 0.825, 0.744, and 0.947, respectively, with the highest AUC value in the combined test group. This study indicates that TEG parameters were highly correlated with hypercoagulability in patients with malignant tumors. The combined use of CCTs and TEG parameters is more effective for diagnosing hypercoagulability. These results can guide the clinical management and treatment of patients with malignant tumors.