Objective: To investigate the effect of extra cardiac valve replacement surgery (ECC) on blood vessel thrombus (TEG) and fibrinolysis in patients undergoing cardiac valve replacement surgery. Methods: From July 2016 to December 2017, 63 patients underwent ECC in our hospital, including 30 patients with autologous blood transfusion technique (the study group) and 33 patients with stored blood (the control group). Hemoglobin (Hb), hematocrit (Hct), platelet (PLT), prothrombin time (PT), thromboplastin time (APTT), thrombin time (TT), fibrinogen degradation product (FDP), D-dimer (D-D), prostaglandin E2 (PGE2), platelet alpha-granule membrane protein (GM-140), and TEG parameters before and 24 h after surgery were compared between the two groups. Results: Before operation, the difference of Hb and Hct between the 2 groups was not statistically significant (P>0.05). At 24 hours after operation, the Hb and Hct values of the study group were significantly higher than those of the control group (P<0.05). Before operation, the differences of PLT, PT, APTT and TT levels between the two groups were not statistically significant (P>0.05). The PT and APTT values of the study group were significantly lower than those of the control group at 24 hours after operation (P<0.05). Before surgery, the difference of FDP, DD, PGE2 and GM-140 between the two groups were not statistically significant (P>0.05). The value was significantly lower than that of the control group (P<0.05). There was no significant difference in the R value, K value, MA value and α angle between the two groups before surgery (P>0.05). The R and K values were significantly lower than those in the control group (P<0.05) at 24 hours after operation. The MA value and α angle of the study group were significantly higher than those of the control group (P<0.05). Conclusion: ECC autologous blood transfusion has less effect on coagulation function, TEG parameters and stability of fibrinolytic system in patients undergoing cardiac valve replacement surgery.