〔Abstract〕 Objective To explore the effect of Maitongning decoction combined with low molecular weight heparin calcium in preventing the formation of deep venous thrombosis (DVT) of lower limbs after hip and knee replacement. Methods A total of 86 patients receiving hip and knee replacement in Zhengzhou Deren Orthopaedic Hospital from January 2021 to December 2022 were selected and divided into a control group and an observation group according to the principle of randomized control, with 43 cases in each group. The control group was given low molecular weight heparin calcium after operation, and the observation group was treated with Maitongning decoction for 10 days. The incidence of coagulation function, hemorheology, DVT and adverse reactions were compared between the two groups. Results After treatment, the prothrombin time (PT), activated partial thromboplastin time (APTT) and thrombin time (TT) in the observation group were all longer than those in the control group, while the levels of fibrinogen (FIB) and D-dimer (D-D) in the observation group were lower than those in the control group, with statistical significance (P < 0.05). After treatment, the levels of whole blood high tangential viscosity (HS), whole blood low tangential viscosity (LS) and plasma viscosity (PV) in the observation group were lower than those in the control group, and the differences were statistically significant (P < 0.05). There was no significant difference in the incidence of adverse reactions between the two groups (P > 0.05). The incidence of DVT in the observation group was lower than that in the control group, and the difference was statistically significant (P < 0.05). Conclusion Maitongning decoction combined with low molecular weight heparin calcium can effectively prevent the formation of DVT after hip and knee replacement, improve coagulation function and hemorheology, and do not increase adverse reactions.